Check out the Wikipedia under Microprocessor. They have lists of all AMD and Intel and other processors, along with the motherboard types that they require or are supported by. From there, just search a computer component sales website for prices if that's what you want.
As for FSB, if you don't know what it means, then I would say it's not that important to you - basically, the bus speed and capacity will affect the speed at which your CPU talks to the peripherals attached, so the higher the better.