Even though a content creator has a valid license for a font, that license may not allow embedding the font in a PDF document for commercial sale or even non-commercial public distribution. The issue is ambiguous, but of sufficient concern that Pat suspended PDF sales of Anomolous Subsurface Environment.
I did a little research, and the key phrase seems to be "free for commercial use". The following links offer more than two dozen high quality fonts that can be freely embedded and redistributed, even for commercial use.
- Font Squirrel
- exljbris font foundry (the fonts listed under "free fonts")
- Open Font License fonts
- League of Moveable Type
- Open Font Library
This font embedding license gotcha is another reason I'm happy with LaTeX.