Great web site for chords, tabs, finding transcriptions, and it has a really neat transposing feature:
Chordie.com

Great web site for finding musicians / bands:
PartySounds

DIY web sites:
MySpace.com
Arkade.com

Web site that discovers and promotes new music, now including podcasts:
DrownedInSound

The book for building your digital recording studio:
PC Recording Studios for Dummies

The best books on the music business:
All You Need to Know About the Music Business
The Music Management Bible

Books to help you build your web site:
Head First HTML with CSS & XHTML (you can just go as far as HTML and get your web site going fully with that – You don’t have to get into CSS and XHTML)
Don't Make Me Think by Steve Krug - Best usability book out there
Building Your Business with Google for Dummies (make sure people can find your web site!)
Marketing Through Search Engine Optimisation – How to be Found on the Web (covers all search engines)
HTML and XHTML: The Complete Reference (once you're more advanced and want to find that elusive tag)

Great usability web site:
UseIt.com