remember : don't use more than 2 or 3 fonts (well, if you're a designer, you'll know what to do with more fonts), and never, please, never include Comic Sans MS in those 3 fonts.
- google fonts : free & ready to use on the web
- adobe fonts : not free, but a ton of stuff, if you're willing to dive into design, may be worth it
- font awesome : icons as fonts
- typography cheatsheet : this is just because I can't help myself but put some typography knowledge in all the resources I give.
- font pair : helps you pairing fonts together
- typo samples : samples of fonts in action together