Here’s a great little tool that we use to integrate in to some of our WordPress website design. It can be a right faff to download PNGs or PSDs and have to fiddle around with different icons and sizes, but Font Awesome is a great tool filled with hundreds and hundreds of really well made icons!
They’re really easy to use and new additions are being introduced in every version. Check them out, they’re free. Just some of the types of icon are below, but there are HUNDREDS more.