I've recently included social media "share" buttons both here on this site, and at macaronics.com (whether or not they serve any useful purpose is another question entirely).
Getting each of the buttons to line up in a simple row is so tricky, in fact, that a bunch of third party services have cropped up to do the work for you.
But if you don't care about having the current number of "likes" or "shares" displayed, there is a simpler way.
For the button images, I used Fatcow's Free Icons for Facebook, Twitter, LinkedIn, and Google Plus.
Reddit and Pinterest both provide button icons (though for Pinterest I had to download the png logo file and scale it down to the same size as the others).