There’s no questioning it, typography is a huge issue in web design. Actually, this is really of little surprise considering its importance in all published materials throughout history, though more significantly in the last century. A choice of font can be used to emphasize things, to convey volume and mood, to look professional or friendly. These days typography is becoming more of an art than ever before as well – many artists turn to it to display their expressions.
Consider these two very familiar fonts, Verdana & Times New Roman, which can convey very different feelings basic on the simple serif or lack of serif on the font. The use of all uppercase or combination of uppercase and lowercase can make a huge different as well.
In the end, when you design you want options. Some of this is an art, though a lot of it can be done well by most people off of gut instinct (in my opinion).
There are currently only 2 predominant commercial free font suppliers in the market: Font Squirrel and Google Web Fonts. My personal favorite, based on better web browser compatibility and selection is Font Squirrel, though Google Web Fonts are not a good idea to ignore. Both are very easy to use and implement into your site, though don’t get carried away as fonts have a significant impact on website load time currently (something I imagine will change in the near future, but hasn’t yet).
Commercial Free Web Fonts
If you have several projects then paying for fonts is not a bad way to go either and can supply you with a lot of very impressive fonts. For this I highly recommend, above all other paid font services and vendors, Adobe Type.