New to this... 40 gallon tank

I'm new to saltwater tanks (but experienced in freshwater), so I figured I'd start with something easy. I'm already hooked though, so I'm upgrading to a 120 gallon in two weeks for my white mouth eel, Jetsam.

In the meantime, this is what I have.

40 gallon
Hydor slim skim skimmer
Emperor 280
80-ish lbs of live rocks
Aqueon preset heater, 78 degrees
JBJ submersible pump
Beamswork LED lights

Any ideas? Suggestions?