I've installed alot of it. At least 100 homes. By far my favorite siding as long as it's prefinished! Hopefully you're getting it pre finished, there's a few brands out there of finish depending on your local supplier. I prefer diamond kote
Don't wait to paint the cuts, they generally give you a few cans like pvc glue comes in with a brush attached to cap. Keep a can in warm area and one by saw and rotate cans as they need to be thawed.
Caulking you could wait till spring but I've done many in middle of winter and works fine as long as caulk is warm until use.
For your butt joints, I prefer to put a piece of aluminum coil stock (8"x8") behind the joint lapping onto previous row so that you only see the aluminum in gap when finished. For gap size use your square as a spacer tool. They might send some plastic h channel to use but personally I throw those away as look cheesy.
During the ordering, make sure that you order 5/4 trim NOT 4/4 trim. That quarter inch is a big deal when caulking your siding to trim, will save much frustration. And nails must be ring shanks. (Assuming your using a siding specific nail gun). Often the lumber yards mistakenly send out the smooth which are for cement board siding, with smart side you definitely want ring shanks. And if you where considering nailing by hand, forget that idea right away.
One last tip, paint a few coils of nails ahead of time that you'll use on your top siding rows and for trim where nails are going to be exposed. Paint doesn't like to stick to cold metal so if they already have a coat of paint on them it's much easier to dap (q tip) a little more paint on the exposed nails to finish/ seal.
