another new mapper

hi, im randomteddybear. my favorite custom map is ctf_convoy. if i have a favorite class it would be medic, but i often play heavy. im new to mapping with source and im getting suitably good at using hammer. but I've been mapping for halo custom edition for 2 years, mostly modeling weapons, vehicles, and scenery occasionaly i worked on a few bsps. but one day i realisd i played alot more team fortress 2 then i did halo. I had to say when first using hammer the concept of making level geometry out of "brushes" came as quite a shock. in halo every thing is made in 3ds max. but so far im doing good at adjusting just yesterday i made some pretty decent looking displacment cliffs but please any tutorails or reasource you think i should know about please tell me