Although, the source engine is a wonderful thing. Its not limited to CS:S (Although its a great game). For instance, there are a LOT of half-decent mods for source games (HL2
M, HL2, etc), including one -
Stargate: TLS. Also,
Garrys Mod -- a sandbox mod where you can code new weapons, tools, games etc through Lua. Also the forums:
Facepunch where people post public scripts, weapons, and you have discussions. Be warned of the moderators and their bansticks, and also make sure you have correct spelling and grammar. If you do thsi (this), you lose points.
You can also Roleplay (On rp servers), where you get money each "day", build shops, etc.
(The new one is $10, but it is a lot better than gmod9 (free). These are some videos for you:
http://video.google.co.uk/videoplay?docid=-3914313767524538936&q=Garrys+Mod+10
The AK for instance, was a scripted weapon (Swep)
Add me on xFire if you need some help (royalmarine0) or steam friends (Same username)