vBulletin skins are simple to add.
It is a matter of downloading the style, then vBulletin will automatically upload the style, add it, sort it, update it - it's all very nice and automatic.
Although you will have to upload all images / scripts manually via FTP.
The
vBulletin.com Forums has a small selection of styles and graphics submitted by members (including me
).
Theres also a few other sites, such as:
This is all I know of. The styles on vBulletin.com and vBulletin-Style are free, as far as I know, also.