I invest through Sand Hill Angels. We are nearly 200 independent investors who share diligence and support of portfolio companies. For a promising company, the group can fill a large portion of a pre-seed or seed funding round. We might also participate in series A or later rounds.
Have questions about the nitty gritty details of startup investment terms? Ask your accelerator mentor. Don't have one? Tome created a great Venturepedia.
Check out the Y Combinator library for a bunch of great advice for startups.