Thank Michigan State University for this Global Resource Directory which tries to sort of "put it all in one place" and keep it current. It was created with the business world in mind, but many of the tools and resources have application beyond the corporate.
READ THIS These websites and databases all provide very different information. It is truly amazing how much information they contain! They are listed here in simple alphabetical order. To get the most out of them, you need to carefully, thoughtfully read the brief descriptions given. You also need to really look at the opening page to make sure you understand everything that is there. You also need to really explore each. This will take time, but it will be time well spent.
FEW BITS OF ADVICE Read the short information given about these sites, especially any tips for using them. In some cases the information you need may not leap out at you when you first open the site. Spend some quality time on the opening page before clicking.