IconsPedia is an online resources to get any Icons for your need, you can download and use all icons from there for free. All icons is created in .ico & .png formats.

It is give you some categorized icons :

Shaboopie is a website that give you a free logo, screensavers, templates, vectors, screen savers and some design graphics more than 80 items. The design very clean, artistic, and nice look.

This site give you free design in PSD files, you can edit and use that as you want for your blog, website and others.