Icons are a great way to personalize the web template you just bought. I've gathered some of the best free icon sets from around the net for you. Some of the icons may have some restrictions like having to place a link back to the creator in exchange for using them or not being able to use them on a commercial site. All of the icon sets are free in some way for you to use.
One of the most popular icon sets on the net today. It's also one of my favorites. I see them on quite a few websites these days. It contains 1,022 16x16 pixel icons.
Inspired by the work of Mark James (Famfamfam), these 460+ 16x16 pixel icons are a perfect fit with the original Silk Icons.
If you need flags for some project, this is the perfect icon set. All 247 flags are 16x16 pixels.
400 more icons in a similar style to the Silk Icons above in both 10x10 and 16x16 pixel sizes.