well im no expert...
but i bought a Zoom RhythmTrak 234 not too long ago. It was cheap but really excellent. It is really user friendly, you can program it in real time or in steps, it has heaps of kits and weird sounds. the only prob is if your into dance you don't have all the effects to add to individual drums. I think Boss have a cheap machine that has really cool effects you can program in real time. but anyway if your looking for cheap and easy i reccomend this.