after a work-less afternoon to written a must be the most longest ramble opinion on all heroes compare to all other steam guide, which personal thought most of them are nonsense complain but
sure include most common idea that may worth you to take a look for while.
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2901742069

0. start match
don't mind how developer change the map, the basic idea are all the same, just grab bounty and start some team fight and stay alive don't do stupid thing, do remember to place ward.

1. early stage
for the basic information, mid lane most time took about seven mins to climbs to levels seven and ten mins for other lane, which when all players on battlefields gotten a side skill fully upgraded and ultimately skill ready to show up then jump in to dominate the battlefield.

2. tier 1 towers defensive
from stage about ten mins to twenty mins middle stage of the match, both side fighting in tower till which side of all three tier one towers be siege down, in this stage pusher hero which capable to quick siege towers in all three lanes and provide higher total net to your teammates meaning your team that insurance higher chance to win the team fight, which critical to faster build the items fat than enemy and snow ball success.

3.mid pushing
till twenty mins and both team focus on 5 mid push to win the team fight, some match are one side winning by successful team wipe enemy several time, some hero like Ursa or Troll could start to tried to took down RS for the aegis stone, or whole team working together to grab RS, beware only did it when enemy be wiped or the when the team own the safe road and you sure it safe to take the RS.

4. the stage to siege Barracks
tried five mid pushing which may got decision victory rapid win by destroy ancient core, but if failure than both side need to tried siege down all three lanes of barrack to insure the mega creep which basic meaning victory for pushing side teams.

5. fairly late stage
from twenty levels till thirty maximum levels, both players need to fight hardly till one side destroy the ancient core , in lately stage both heroes struggle on fight and it's death punishment are huge as the death timers count need to wait higher around hundred higher of seconds to respawn, there still occasionally happen reverse win due to the enemy side whole team wiped punishment, make sure prepare buy back money and stick close with your teammates that lead victory to your team.

For a early stage player personal list out some basically heroes pool for you to choice with.

Naga
weak:axe, lina, sniper which good at Aoe or nuke hero which could dash out damage which clear out illusion before did anything work.
anti: bane, which main the single enemy would had difficult time against you
core item: Diffusal Blade, which provide you a addition slow disable, plus the mana break effect let enemy hero lose mp.

Phantom assassin(PA)
weak:every nuke spell damage which harm direct by using pure magic damage
anti: everyone who alone.
core item: BKB, grind it out as fast as you could, because pa the only weakness are the nuke magic, so when you start hold the BKB which meaning death ring to your enemy.

Dragon knight(DK)
weak:sniper or any nuke ranger which hard to counter it back
anti: ss, which couldn't even hurt you due to your own the highest hp and armor in this game
core item: Assault Cuirass, which because you are the tank in team, AC provide both buff and debuff of the attack speed and armor, by buy it your could start leading your team into battle on front and win.

Shadow shaman(SS)
weak:PA, which can handle the disable spell and still dash out massive damage and kill SS before retreat.
anti: low hp hero, SS could easy handle multiple enemy by disable spell and use the ultimate skill to siege push.
core item: Octarine Core, which give your skill decease cold-down time which allow SS to spam the ultimate skill everywhere without need to concern the spell cold-down times

since there are near 124 heroes so I written it at another single guide like below.
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2901745682

for those people who confused by the huge items list and can't made up your decision below is my suggestion, for the start you only need to focus a main items which are the best item thought out the whole game, you must choice the start core item which would cover the badly weakness of your hero and became a snow ball to help your build other item even harder.

here the basic idea how the level and items progress, your should up too levels seven which about around ten mins, after that your already got the core item and level full your core spell and ultimate skill are ready to work, the heal and ward items are necessary so buy it yourself.

strength hero
BKB: for player who need to dash out the damage and avoid enemy use spell to counter
blade mail: due to the enemy ranger attack, this item could counter the ranger hero such as sniper.
Heart of tarrasque: CK main item which this item not only recover your hp at crazy rate but also provide power to battle enemy carry
abyssal blade: for basic melee like Sladar offer the bash, could provide higher power to stunned your enemy.
Assault cuirass: debuff and buff the armor for all units in range, hero such as sven could help the teammates when in the large team fight.

agility hero
Diffusal blade: for those own the illusion hero which could burn enemy hero mp, it also provide a slow spell for you to use.
Satanic: agility most own the faster attack power in general, which this item could leech back hp when in team fight which keeping you alive.
Buttererfly: fairly easy item which provide the evasion, movement speed, attack.
Shadow blade: for the ranger in agility such as DR, Sniper, this could let your invisible and initiated the enemy, you could flee from enemy hero chase too.
Monkey king bar: pick this up if your found envision heroes like PA give you trouble

intelligent hero
Refresher orb: for those hero like SS, Enigma, Warlock which own a powerful ultimate skill that let you using it twice at time.
rod of atos: root the enemy hero which allow teammates help take down it.
Aether lens: most of the intelligent would need to start this items which help massive the quick you grab it up include the cast range and mp regenerate.
Octarine malevolence: hero like Qop could rely on this to silenced and dash damage to enemy in a safer way.
Linkens sphere: when there are powerful skill in enemy team like LC, Lina, BS which hunt the fragile target and which I meaning you, best build this item ASAP or your gonna have a hard time to fight with enemy in rest of match.

The ranked battle have two rule to apply as I list down below lane.
1. two ranger, two melee, one mid
2. two durable, two nuke or disable, one initiate or mid

below are some recommend team set which may come in handy if your need to decide which teammates heroes to pick with, a friend to play with and communicate is also a option that gonna
provide improvement game expressive much batter then solo gamer.

Team standard
Axe, LC, PA, Zeus, SS
pretty standard teammates which own the most of basic hero, could handle most of the situation.

Team roaming
CK, Tusk, Sniper, Naga, lina
carry hero which rely heavy on cost spell and go in then out battle easy, meaning less punishment happen when start the team fight.

Team shadow
Omni, Slark, viper, DR, BH
most the dps output own more than one which could inadvisable and flee or initiated battle easy.

Team ultimately
Jug, Np, Bane, Enigma, WD
I pick the most broken and powerful ultimately spell form the list of hero, not only it effect globally when apply but them could using it to dash or interrupt fairly easy, I say this team setting broken Dota 2.

Team joke
Chen, IO, NS, Embar, Riki
no I not joke about this, tried to win a ranked match with the five of most horrible heroes combination

• Necrophos: gain health and mana regenerate, you gained even even more harder by kill enemy.
  
• Pudge: passively grants bonus strength permanently
  
• Axe: gains bonus armor permanently
  
• Slark: permanently steals 1.0 Agility on each kill
  
• LC: duel winner gains permanent bonus damage, now effect whole team.
  
• Silencer: Permanently steals 2.0 Intelligence.

• the best of team set up are two melee and two ranger plus one mid player, not always accuracy but at least it work for most of the match.
  
• team work are batter than solo or spit push, when teammate say five mid pushing their meaning it serious.
  
• spit push and grab RS are the idea when wiped out enemy teammates, else it's not the priority thing to be handle, and it's may became very danger situation to take RS when enemy force is closer to you whole team which may happen heavy punishment leading not just lose RS and lose the match.
  
• position yourself before initiate the battle which may save you or teammates a life.
  
• chat wheel could quick info teammate with the battle info such as missing lane or apply gank before fight, call out missing when enemy went gank other lane, call out you position or action are also a option to help the team fight.

The first guide for new player
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1502268374
All heroes guide
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2901745682