Since Hurricane Irene and the immediately ensuing rain storm, the center of my basement floor is now higher than the intersection of floor and walls. Cracks have developed radiating out from the center (and connecting with one another). Water seeped in through those cracks and through the joint between floor and walls, flooding the basement floor. It's now drying out, but cracks remain.

Can I fix the floor and the floor/wall joint myself? If so, how? If not, what do I need to know to hire a contractor and get the job done right?