I'm not sure you really need the expense of a lawyer.
I'm based in the UK, my contract is a simple three page affair, simple, to the point and easy to read and in plain English. It's pretty air tight and keeps both sides happy. I'm sure some expensive picky lawyer could find something wrong with it, but it works perfectly for me and I'm happy with it.
I do make alterations to it from time to time depending on the client.
Obviously the law in the UK is different to the US, but I'm sure you'll find a bundle of resources out there on the net.