IconSweets 2, a project by Yummy gum is a huge free icon collection that contains over 400 icons in photoshop vector shapes. The icons were created in 64×64, 32×32 and 16×16 pixel sizes. The website states you may use these icons for both commercial and non-commercial projects and customize them any way you like. This has to be one of the best icon collections I have come across.
Glyphicons
GLYPHICONS, created by Jan Kovařík, is a large library of monochromatic icons and symbols. They are designed for applications, web sites, web applications, infographics and more. Currently there are three package options to choose from – FREE, ALL and PRO (which includes vector versions).
Premium Pixels
Premium Pixels was created by Orman Clark, a web designer based in the UK. The website provides exceptional resources for designers which are offered free of charge. Orman even goes so far as to provide free PSD versions of some of his very popular WordPress themes.
Spyrestudios
Spyrestudios is an online magazine founded in 2007 by Canadian web designer Jon Phillips. The website includes interesting articles, detailed tutorials and inspirational posts about web design, web development and all things related. The site also has a great selection of freebies.