What you will need:
Canning Kits that include all sorts of things to keep you from burning yourself, and a funnel are available at big box stores (including Lowes) or online for $10-$20.
ALSO keep all your tools together (I store mine in my pressure cooker out of season so everything I need to can is right together.)
Water Bath canning will ONLY SAFELY work for highly acidic foods like jams, jellies, and pickles. If you only plan to can those items- a water bath only costs about $20, but if you can other items, like vegetables- you may get botulism or another serious food born illness.
Pressure Canners are recommended for ALL canning by the FDA. You can water bath can in a pressure cooker as well (just leave the lid off.) The pressure canner is a much bigger investment at $80. I have the Presto 23qt Pressure Canner. It holds 8 qt jars, or 6 pints at a time.
Purchase your jars based on what items you would like to can. Some recipes only give instructions for certain jar sizes (yields 6 qts) in which case you should use the size recommended in the recipe for accurate processing times. Wide mouth or traditional shaped jars are totally up to you. I find wide mouth jars are easier to fill, and prefer them for whole vegetables like tomatoes and okra, but for sauces, jellies and cut vegetables the traditional shape will work fine (you'll be glad to have a funnel though!)
You can reuse any jar that was made specifically for canning- not commercially canned items even if they look similar(which means if you save your jars, you can reuse them next year.) You ONLY reuse the glass part and the metal ring. The seal can only be used once and you may discard it after use unless you plan on storing something that does not need to be air tight. Obviously, don't use chipped jars because they cannot seal. Replacing the sealing lid is very inexpensive so save your jars. (I put mine back in the divided box they came in after a trip through the dishwasher.)
If you are pickling, or plan to salt your vegetables in the can, use pickling/canning salt because it is not iodized. The iodized salt will make the vegetables appear darker and the water seem cloudy. It will not affect the flavor though. If you cannot find pickling salt, you can use kosher salt or un-iodized salt- be careful about measurements of kosher salt though because it does not pack as evenly in the measuring cup because it is coarse, you may need to use a little extra or make your measurement heaping.
Okay, so if you are feeling overwhelmed right now, and are wondering if canning is for you- here are a few things to consider.
Obviously for most people the initial cost is kind of high, but it will be significantly less the following year.
Canning was the only option before freezers. Although the only way to make a preserve pickles and jellies is with canning, you can freeze most vegetables, which is a lot less work. See Freezing instructions below. Freezing also works well if you are growing your vegetables and will not have a large amount at one time.
Do you have time to can? You should plan on dedicating at least a full day to canning. You want to can as much as possible at one time because of the set up time (boiling the water mostly.) I usually prep the next vegetable while one is processing.
So if you have decide you are ready to take the plunge and can
Blanch (3 minutes in boiling water, then immediately into a bowl of icy water to stop the cooking).)
Drain in a colander (you may even want to lay them out on paper towels.)
Bag and Freeze (based on portions) with as little air as possible.