Congrats on your New Nolting. My 24" Pro is going on 13 yrs and is a true workhorse. You will love it. I baste the top and sides as I quilt the top. I add a sacrifice border of muslin on the bottom of the top so everything is nice and tight, no ripples when you get to the end.
If I am doing a custom quilt that requires alot of rolling back and forth, then I will baste the entire quilt so your back will stay nice and smooth. My basting for this is real close,like 4-5 inches ..too far it will cause wrinkles on the back. Alos check your backing and batting when you advance the quilt. Give the batting a tug to smooth it in place, they get wrinkles and you can't see them til it is too late.
I never float my tops however this is a personal preference of the longaramer. You will find out what works best for you .