Buy the Hanon book and work on the finger exercises. Hope this helps.
Just what I was going to suggest. The Hanon books (there's 100 volumes, I believe, 1 is the easiest and they get harder as the numbers increases) are books that are designed to help the accurancyof your fingers and strengthens them too, this series is what many classical pianist use. There's also another series, it's by a Russian, but it's great too. With both books, you have to be able to sight read because it's on a grand staff.
You can find Hanon at a music store that sells classical sheet music or choral sheet music. You can also buy it online, use google to find.