There's a few plugins floating around for 3Ds Max, they all give you the same end result it's just a matter of personal preference as for which one to choose.

http://www.wunderboy.org/sourceapps.php#max_smd

http://dev.wallworm.com/topic/2/wall_worm_model_tools.html

http://www.chaosincarnate.net/cannonfodder/3dsmax.php

The rough layout of how to do it is:

1.Make model
2.UV model
3.Texture model (preferably all in one texture file)
4.Export model using plugin to the .smd format
5.Convert texture to the vtf format
6.Make a QC file
7.Compile it
8.Redo the previous steps to fix up the model in various ways

Biggest advice I can give is to make sure your folder paths are setup correctly almost half the time I have a problem it's because I messed it up somewhere down the line.

More info here:https://developer.valvesoftware.com/wiki/Category:Modeling