Just registered, links would be helpful.

I want to make map for half life that is single player only, has triggers like sound effects, explosions, text on screen, ability to pick up certain items, how can I do that with Valve Hammer? I already have made the simplest of maps for Counter-Strike but I am clueless on where to start for making a single player game to be used in Half Life. Also;Can I make a single player like game for Counter-Strike? i.e. can use the guns from CS...

Thanks, shake