Congratulations, you are now officially in "Hot Water", now relax. 80% of everything you need to know will fall right into place, it's the 20% that you need to inquire about. Once the tub arrives and you get electric to it, get the hose out and fill it. If there is anything to clean out, by all means clean it out, althoough I would expect it to be delivered clean.
Once filled, power it up. It's going to take some time to come up to temperature. This is a good time to test your water and put in some di-chlor.
Now call your dealer and clarify any questions that have come up during your getting acquainted start up procedure. There is really not much to it and it should all fall right into place.
Soon you will be soaking in leisurly comfort and counting the stars.