I would recommend that you start s-l-o-w-l-y and do only one simple item/recipe at a time. Start with canning tomatoes or jam. These are easy, meaning; they don't require a lot of equipment or processing, the jars can be sealed using "Boil Bath Method", and you will have successful products. Which is important, because you want to like what you preserve and have gratification and satisfaction in an accomplishment well done.
Now canning is not as expensive as it might seem, if you plan, watch, be organized, and follow a few simple things.
1. If you start with canning "high acid" items that can be sealed using the Boil bath Method, then you can use a deep stock pot that you already have. As long as, there is at least 2 to 3 inches of room above the jars to the rim of the rim of the pot. This is so that you will have enough room for at least 1 inch of water above the jars and space for the water to boil without spilling over.
2. Watch for canning jars at thrift stores, yard sales, tag sales, flea markets, craigs list, local newspaper, etc. I am always picking up a jar here and there. Before you know it you will have several dozen. I have target prices that I try to limit myself too for different jar sizes. Quart size .75 cents or less each and pint and half-pint sizes .50 cents or less each. Just make sure and check that there are no nicks on the top of the jar or the lids will not seal.
3. Each year, early Summer and late Fall, the Sunday newspaper will usually have a coupon for $x.xx amount off 2 cases of Ball/Kerr canning jars. This is a great deal, since it brings your cost down to right around my target price for used jars and you get the band and a lid.
4. Check out your local discount stores for jars, lids, and bands. Some stores that I frequent are Fred's, Dollar General, and Wal-Mart. I recently found standard lids at Fred's for $1.00 box/12. Wal-marts price is about $1.50+ a box. So, I brought home 20 boxes, They are an off brand, but I have had no trouble with them not sealing.
5. Plan to continue canning. This is an investment, not just a passing fling. You will get the most for you money if you use and reuse your jars and equipment. One of my pressure canners was my grandmothers. So there was no investment in it by me, except to have pressure gauge checked periodically. I also have jars that are 20+ years old still in use. You have to be careful with how you store them when they are empty, so as not to chip the rim. Other than that, good jars will last a long time.
I do hope this gives you some ways to begin or expand you home canning endeavor. Just remember, start slow and simple, otherwise you might give up to soon. Keep you thoughts to how wonderful home canned food tastes. It is so much tastier than store tinned. And the benefits of having food items without all the added preservatives and chemicals, especially if you use organic fruits and veggies.