Some nice free of charge font sites include 1001 Fonts and
1001 Free Fonts.
Once you've chosen your favorite font, click on it to download. A box will appear - choose Save and find the destenation in which you'd like
to save your font in. Afterwards open the folder and unzip the file into your fonts folder (click Extract and extract to C:\WINDOWS\Fonts).
The next time you'll open a program, make sure to search your newly added font in it ;) It may take a while to load the font into your comp,
but as long as you followed these steps everything should be just fine :)