Merlin Mann of 43 Folders fame has written an excellent article about the biggest mistakes musicians make when creating their web site:
Too much Flash
Okay, I get it. You’re creative. Awesome. But you’re totally wasting my morning as I helplessly wait for your designer’s dancing sausages to finish loading. Perhaps worst of all, most all-Flash sites prohibit your fans from creating deep links to artist, album or song pages. Your fans are trying to drive people to the cash register, but you insist on making them watch a puppet show before they can even enter the store.
Crappy or non existent mp3 metadata
If I load up the mp3 of your big single and it says it’s “Song” by “Artist” on the record, “Album,” you’ve completely blown it already; I have no way to ever find you again. Ditto for file naming. Remember: people often download dozens or hundreds of songs at once, so it’s really unlikely they’ll remember where Track%2007.mp3 came from.
Too artsy, too fartsy
People are visiting your site because they want to learn more about bands and music—not to have a guided tour of your designer/brother-in-law’s Photoshop brush collection. Don’t be cute with the design, section naming, or navigation. Don’t make your visitors solve a Rubik’s cube to pull up your lyrics page.
No search
Chances are good that fans coming to your site arrive with something extremely specific in mind—often a fragment of lyric or the name of one obscure song. If your site contains more than a handful of pages, provide a clearly labeled search box (or link to a search) on every page, and test it. Make sure your search works and drives visitors to your most popular pages without the need for pecking around.
One-way communication (served one way)
Your fans are not empty vessels or just (ugh) a street team; they have things to say too. Provide a clear contact email address (plus separate ones for press and booking inquiries if you’re all famous and whatnot) and consider having a fan message board and mailing lists for tour and release updates. Read your email, and answer it.