http://www.dafont.com/ is a good place to start.
To install using XP:
1. Download the file and extract it anywhere
2. Open up the Fonts folder (C:\Windows\Fonts)
3. Drag and drop the font in the extracted folder into the Fonts folder
To install using Vista:
1. Download the file and extract it anywhere
2. Right click on font and click "Install"
3. UAC should come up, allow it, and you're set.