I know there is bad stuff as well as good stuff to start growing on the rock.
I'm just not sure how to tell the difference. I know coraline algae is good stuff. Are there pix anywhere as to what i should be looking for?
As long as you don't get red slime algae (which is not really an algae) you should be okay. Go over to the Hitchhiker forum and just start clicking threads and you will see all kinds of stuff that shows up with live rock.
Given quality water and chemistry, you should start to see them in about 3+ weeks. If you don't, there may be something too much or not enough in the water.