Another nice site for tut's would be
UnrealWiki
This site may be kinda difficult to browse through if your new to Ued, but certainly is worth to check out. Also, you can download the entire site content in a offline package.
(if you own a (dvd) Special Edition of ut2004, then (VTM's)
Video
Training
Modules are included..if not, check below)
And.. a really nice site is
3DBuzz which has lots of VTM's available for download about Unreal technology. It covers more than just mapping. It's explained very detailed, easy and understandable and IMO much better than the average written tutorials available.
Note: you must register (free) before you can download any VTM's. The site has lots of other VTM's for other pograms as well.
Good luck!