all this is good info, and lots of other good info in this thread too.
The main thing is don't just buy the gear and assume that you'll learn to use it through experience. I put a LOT of emphasis on the importance of taking an AIARE avy course because its where you are going learn standardized, time tested techniques for both studying the snow and understanding it, as well as rescue techniques. Also, if you ever want to guide/ patrol, you're gonna want that on your resume.
as far as things that I carry in my pack?
1. REPAIR KIT:
-*leatherman*
-baling wire
-multiple screws of different sizes
-small roll of duct tape
-safety pins
-whatever else you can think of that might help in a pinch.
very important, because if shit hits the fan equipment wise, you are gonna want some materials to jerry rig something that will work to get you home at least.
2. packable synthetic down layer.
if you get injured, or for some reason have to stop for awhile (i.e., fix your bindings, dig a pit, etc.) you are going to get cold, fast. Synthetic down (primaloft) will keep you warm even if it is wet. It's not something i pull out all the time, but in a pinch, you're gonna want it.
3. FIRST AID KIT.
kind of speaks for itself, but also, know how to use the stuff in it.
4. space blanket.
I have a great one from ortovox that is like a big bag that can fit two people, be used as a tarp for building a shelter, and its also reflective and bright, so you can use it to flag down help.
5. Snow study kit
you'll know what to do with this once you've taken you Avy 1 course!
6. monocular
comes in handy when trying to scope terrain (i.e., for natural slides, windloading, sick drops and whatnot)
and of course shovel and probe.
thats all I can really think of right now, i'm sure theres more shit.