Crunchbase: offers a newsletter that provides information about startups and fundraising; also has investment listings for all public and private companies so you can see who funded them and when
Pitchbook: provides data about VC, PE, and M&A transactions, including public and private companies, investors, funds, firms, and people
AngelList: a platform for startups to raise money online, recruit employees, and apply for funding; also has a good blog