Ha I didn't know all this either. I purchased a Schefflera from Lowe's, it's one of the Exotic Angels Plants collection.
I was quite small when I bought it just a couple of months ago - just 1 stem. I've repotted it once since then, into a 8" pot, and darned if it doesn't need it again - it's 3 stems now!
I didn't know you could split it up. Is it ok to do this before it gets cold or should I wait til spring now?