Dweste -
Others have said this as well, but a lot will depend on the regulations for where you're going. If you are going to Yosemite, SEKI, or other locations requiring bear canisters, you absolutely must bring them (you can rent them for cheap at REI and other places - sometimes at the ranger stations too - so buying isn't an absolute must). It's as much for the health of the bear population as for you.
You can skip the bear spray in California - that's for Grizzly bears.
Canisters are so much easier than hanging, I use them in bear country even where they're not required (and sometimes an Ursack, a kevlar bag that can be used in some areas). But hanging is an option in areas where it's still allowed, as long as you know what you're doing and have a bit of extra time to get everything all set up.
I wrote the article on bear canisters and food containment in the fall issue of Backpacking Light magazine, and did interviews with many agencies about bear behaviors, requirements, testing and so on. Ping me off list if you want more info.
- Steve