First is the Period Table of Typefaces, which organizes the top 100 fonts by family and class like the elements are organized on a conventional periodic table. You can find a large version here that lets you zoom in to read the rank, family, designer, and date of creation for each font.
Neato idea…and thank god Comic Sans didn't make the cut.
If you have a font you'd like to identify, What the Font and Identifont are worth checking out. What the Font allows you to upload a document with the mystery font and if their website can't automatically identify it, their "cloak-draped font enthusiasts" will try to figure it out for you.
Identifont helps you identify fonts by asking specific questions about the characters. You can also look up fonts based on similarity to other fonts.
It took me 3 tries to get the Harrington right, but it worked in the end. At least you know when it's wrong because they show you the font they think you're describing.
Finally, you can easily make your own fonts at YourFonts. I tried it out myself. The process was super fast and they gave good instructions for installing the font.
Parents, beware the next generation of forged permission notes…