A great thread has been growing on Hacker News about the best place to find start up jobs. I've include the mentioned websites at the bottom of the post - but wanted to first give a couple higher level comments:
1. Read and participate on blogs. Fred Wilson commonly posts about openings in his portfolio and did so again yesterday. Reading his blog (and others) can inform you of opportunities - participating on his blog (comments, linkbacks, etc) can help you build credibilty. Secondly, most bloggers make their contact information available. My email is on the left side of every post and I, for instance, have job opportunities available. Read and be aggressive.
2. Most major blogs (like TechCrunch, GigaOm, etc) have job boards and have company indexes. Browse each. If a company is particularly attractive, visit their site and their job board.
3. Classifieds sites work - particularly if you live in the Bay Area. Craigslist and Kijiji have tons of listings. Search regularly and set up rss alerts. You can also be more proactive and post your resume.
5. Network. Network. Network. Upcoming and other sites list start up events and conferences. Attend, engage and carry business cards.
6. Don't be deterred because a company has no job openings. If you're smart and are a great fit, they'll take you. You can never have an excess of excellent people (at least that's my view).
Best resources to find start up jobs (from Hacker News):
- TechCrunch's CrunchbBoard - CrunchBase - Hacker News Jobs - Sequoia Portfolio Jobs - KPCB Portfolio Jobs - HotStartupJobs - Startupers.com - Jowba.com - Go Big Network - StartupLogic.com - npost.com - SnapTalent.com