Q2 modeling and coding, cool.
Did you use QuArk or are you a Hammer user?
Ignore all the lame stuff above, We have had a spate of questions like "Help fix my box, it doesn't work" and the 'old members' are getting a bit frustrated. So please don't take offence, they mean well
For a really general idea of what you need to get mapping (and ultimately produce your own Mod) have a look at
Where to start.
And for app's try
LinksDon't listen to SilentGunz...
Quake celibrated it's 8th Birthday last month as I am sure you are aware, while everyone rushes off to be part of HL2 (or DooM3 even) there will still be people Modding and Mapping for HL1.....