Some HD Videos I made for people to start mapping for HL2/Source using the Valve Hammer Editor.
These Beginner videos pretty much cover everything you'll need to start building/mapping for any Source engine game (Portal, TF2, Left 4 Dead, Half-Life 2, Counter Strike, Day of Defeat).
HL2 Mapping - Beginner Tutorial 1 (Making, Compiling, and Running a Basic Room)
http://exposureroom.com/HL2-Beginner-1 (Full Resolution Streaming, also allows Downloading)
http://www.vimeo.com/648712 (alternate link, much lower resolution streaming)
HL2 Mapping - Beginner Tutorial 2 (Basic texturing, and adding a Hallway to another Room)
http://exposureroom.com/HL2-Beginner-2 (Full Resolution Streaming, also allows Downloading)
http://www.vimeo.com/752415[/url] (alternate link, much lower resolution streaming)
HL2 Mapping - Beginner Tutorial 3 (Adding a Door to your Hallway)
http://exposureroom.com/HL2-Beginner-3 (Full Resolution Streaming, also allows Downloading)
http://www.vimeo.com/752432[/url] (alternate link, much lower resolution streaming)
HL2 Mapping - Beginner Tutorial 4 (Adding enemies, weapons, and creating an interesting combat environment.)
http://exposureroom.com/HL2-Beginner-4 (Full Resolution Streaming, also allows Downloading)
http://www.vimeo.com/753735 (alternate link, much lower resolution streaming)
Comments are appreciated.
I'm going to be starting some more tutorials soon. What specifically would you like to see?