It should be noted that if you have bought a pair of running shoes then it is a crime if you don't also wear a good pair of running socks. They fit better, they wick moisture away from your foot, they are breathable and prevent blisters plus they can be cushioned and are very very comfortable.
There is a lot of choice when choosing running socks but basically if you suffer from blisters then choose a twin skin sock that will help absorb the friction generated between your skin and the sock. If you want extra cushioning for whatever reason then choose padded socks. And if you want a summer or racing sock then choose a lightweight breathable sock.
And if you simply want the best running socks money can buy, then choose X-Socks. These socks have got everything from a left and a right anatomical fit, anti-bacterial properties from a silver footbed, air channels, padding and a highly-wicking fabric and expertly designed fit.