FreePik and Flaticon are great sources of vector graphics and stock images.
Some of their graphics have been incorporated into this website.
More than a million free vectors, PSD, photos and free icons. Exclusive freebies and all graphic resources that you need for your projects.http://www.freepik.com/
Download all icons in SVG, PSD, PNG, EPS format or as webfonts.http://www.flaticon.com/