Steve - dogwood is a good choice. I have been using Red Osier for several years now, and it makes some very good arrows! They're incredibly tough and resilient, and the material is easy to work with. I have experimented with cane, but not enough to claim proficiency. From what I can tell, cane arrow making is an art form in and of itself. Cane is an amazing arrow material. If you have it available, use it. I would suggest you check out PaleoAleo's cane arrow tutorial on YouTube.
When I was first starting out I read everything I could find on making primitive arrows, but the book that helped me out the most was Jim Hamm's "Bows and Arrows of the Native Americans". Lots of good information. Also, Jay Massey's chapter on self arrows in TBB-v1 is pretty good. After the research, you'll need to get your hands dirty and start making arrows. Don't expect your first attempts to be perfect. You'll make mistakes, learn from them, and before too long you'll be turning out very serviceable arrow shafts.
As far as judging spine, I have always done it by hand. Just flex an arrow that is the correct spine, and compare your other shafts to it. It takes a little practice, but you get the hang of it pretty quick.