This could use a little revival.
Team fortress 2 stuff:
http://developer.valvesoftware.com/w...Level_Creation
Terrain:
http://developer.valvesoftware.com/wiki/Displacement
And some basic shit legionaire dug up
http://developer.valvesoftware.com/wiki/Your_First_Map
http://www.moddb.com/games/half-life...-hammer-editor
And you can find just about anything you else you might need here.
http://developer.valvesoftware.com/wiki/Main_Page
On another note I made a level for tf2 today :awesome: