For a bearded dragon, you'll want a ReptiSUN 10.0 fluorescent tube bulb (not a compact or coil, they can cause eye issues) for UVB and a heat lamp. My dragons have a 75 watt household bulb for heat and they're each in 40g breeder tanks, to give you an idea.
For the ReptiSUN bulb, you can get a fixture at Wal-Mart called "Lights of America under-cabinet fixture" of appropriate length (I use a 24" bulb for a 40g breeder tank), take out the bulb and plastic that comes with it, pop in your ReptiSUN UVB bulb and use double-sided velcro to mount it on the inside of the tank. Looks great, and works wonders!