To completely reiterate what everyone else said, here's a little reading for you, at your leisure ;)
http://www.furious.com/perfect/vinyl43.html
http://www.furious.com/perfect/vinyl43.html
Perhaps a dumb question...
What exactly does a phono preamp do? Remove noise? Clear up dynamics? What is the purpose? I've noticed even my school's relatively cheap listening rooms uses a very basic phono preamp, I'm just interested in what exactly the effect of it is that makes it worth spending money?