From this Robservatory post about Font Squirrel:

They offer a huge assortment of fonts, all licensed for free commercial use, with a nice set of categories and search engine. And free…though the tradeoff is a fairly heavy advertising load.

And:

Font Squirrel not only has a great collection of fonts, but they offer a free web font generator. Using the generator, you can create fonts that are embedded in your page, so that they’re available even when users don’t have those fonts installed locally.

There’s more to Font Squirrel. Definitely worth a look.