read lordroads sticky in the nano section, very good info there. i'd say live rock is required for a 10g. its the best total biological filter, and will be the most stable option possible for a small tank like this. if you go slow, take your time, and be thorough it shouldnt take more than a couple of months before you tank is stable and fish ready. once there, you can probably keep 1 small clown in a ten. maybe another fish like a gobie too but thats it. I recommend the false percula (also known as ocellaris) clownfish. they are very hearty and resilient, an ideal first fish. cant state this enough though, wait until well after your tank cycles twice: once with just live rock and once more with clean up crew.