but then they start talking about PH and headspace, Botulism and all that.
It's not all that. Acidic products such as fruits and tomatoes get a water canning, and anything else gets a pressure canning. Follow a recipe and you're good to go.
Start with tomatoes because they're easiest. And so is applesauce. Here are some recipes and tips:
Freshpreserving.com -|- Your complete source for all fresh preserving needs.
BEWARE:
One year my step-mother-out-law sent me over boxes and boxes of gorgeous tomatoes from her overly ambitious garden, so I decided to put up some spaghetti sauce. Hours later (and I'm talking at least 12 or 14), after I'd blanched, peeled and seeded each tomato, chopped and seasoned, and cooked down to a good thick consistency, then processed - I ended up with maybe 6 qts of sauce.
Granted, it was the best canned spaghetti sauce in the world, but....yeah.
Anyway, good luck! It's fun to say you put up your own whatever, but once you've done it you find it's best left to Del Monte and Ragu.