Thrift stores and garage sales are good sources of canning jars. Run your finger around the rim to check for nicks that will prevent sealing.
Buy lids and rings in bulk to save money, or invest in Tattler lids and rings, which are reuseable many times over.
Don't be afraid to buy used pressure cookers (but know what to look for).
Boiling water bath canner can be any pot that's deep enough to cover your canning jars with water by a couple of inches. Your soup pot will probably work just fine.
Funnels make the job easier, but any funnel will do as long as it's big enough for produce to go through.
Lid lifters are sticks with magnets on them. That's easy to create.
And there you go. Wow, how much did it all cost? Less than a few cases of canned vegetables on sale.
Where to get the food? Grow your own or pick from the wild, gladly accept other's overabundant garden produce. Go to the farmer's market at closing time and see if you can make a deal with those closing up for the day.
Watch your local Freecycle.com and Craigslist.com and keep an eye on your local newspaper for freebies or low cost produce.
Don't know how to can? Don't despair; use the tips here to get started: Learning Canning
More about buying used canning equipment
Look at what others are canning
How to use a pressure canner, step by step
Canning in a boiling water bath canner
Photo courtesy Morguefile.com