It's adhie, not Adhie.
I've started making maps for CS:S first, mostly smaller surf and aim maps. At this time I learn't how to use Hammer. Love'd doing it. Little later, when Portal came out, I bought it and started making simple puzzles for it too, but nothing bigger. Then i made some (exactly 3) surf maps for Portal, that was fun, but i never published them. After that I bought HL2 and the 2 episodes. That's where started looking at the hl2 source code. Now I'm making an own MOD, but it's running slowly, cause, I have scool, work & stuff u know. I'll let you know about my results.