One thing I have learned the hard way ( many FET's later ) is that if you do an H bridge for a single supply, design in switching for the FET's that makes it impossible to fire both FET's on either side simultaneously, or you short out the supply. Using FET's with built-in reverse diodes helps also. Most MosFets ar like this.
You can prevent the short out by using OR logic gates in the drive circuits or by using a bridge driving IC. You can get self limiting FET's ( current and temp ) that are logic level drive, something like a BUK102, or a VNP49n04 from ST Micro. They have good data sheets and design ideas also you may want to look into. i use the VNP's in a H bridge on 10 amp motors that reverse, and draw a stall current of nearly 50 amps, and have yet to smoke one of these FET's. I use a micro to control the switching.