Icons have been around for a long while now and customized icons for the web are becoming more and more popular as time goes on. They do an amazing job to train the eye and help draw out the most important information. The most important aspect of designing an individual icon is that it has to be instantly recognizable, you have to know its function, and you need to know exactly what it is. If you are designing a set, the actual design becomes a lot harder, you have two challenges: each icon you design has to be individual and distinctive from the other, but at the same time they have to have similar features to show that they are related, making a complete set.
Here is a selection of free high-quality icons that are available use. Don’t forget to read license agreements before using icons in your designs – they can change from time to time.
E Commerce Icons
Social Networking Icons
General Usage Icons
Big windows 8 icon set with near 15000 Windows 8 icons, including all sizes, following windows 8 guidelines, several variations, pixel perfect and vector sources.