Here's the most important advice we can give: Your goal isn't to fix your car.

That's right.

Your first and most important goal is to walk away from your car at the end of the day with all digits, appendages and eyebrows intact.

Your second goal is to not blow up anything or anyone else.

Your third goal is to not break something that's not already broken.

Your fourth goal is to fix what's broken.

Here, then, is our advice for successfully achieving all four of the Car Talk Do-It-Yourself goals.

1. Start simple.

Start with the easiest repairs first. Don't dive right into rebuilding your transmission. You'll gain confidence, learn how to use tools and begin to understand how everything fits together on your car.

Here are some great repairs for novice shade tree mechanics, in order of increasing difficulty:

Replace the wiper blades
Change the air filter
Change a headlight
Change a battery
Replace the spark plugs
Change the oil
Change belts
If you're undertaking a repair that's not on this list and you're just getting started, at least make sure it's a repair that doesn't require you to lie on your back, deep underneath your car.

If you have to jack up your car to get underneath it, under no circumstances should you use the flimsy jack that came with the car. And never, ever get under your car unless it's supported by approved jack stands. (Unless, of course, you can get your mother-in-law to hold the car up. In which case, we'd like to see photos.)

Finally, when you're getting started, try to avoid repairs that involve contorting yourself into an uncomfortable position, which can make a repair vastly more difficult.

2. Avoid repairs with dire consequences.

Try to avoid repairs or service work where the consequences of a mishap are great. For example, don't try to replace your brake master cylinder or fuel line on your first repair. You could end up crashing into a plutonium tanker. Or be self-immolated. Or worse still, you might wreck your engine.

3. Get the tools you need.

Before you start ripping apart your car, go out and get a set of tools, including:

A complete set of socket wrenches, including swivel sockets with extensions of various lengths and angle accessories.
A complete set of open-end and box wrenches.
The usual screwdrivers, pliers — and especially, a good set of vise grips.
Whatever special tools are necessary for the job you're contemplating. For example, a special tool is necessary to remove the oil filter, and another for the spark plugs. In both cases, there are different sizes of tools, so take a look first and find out what you'll need.
No matter what tools you buy, you still won't have all the tools you'll need. So our final piece of advice is to start your repair early. That way, the parts store will still be open when you head down there looking for that special, Fiat metric xenon fog lamp wrench.

4. Do a little homework.

Do some homework before you plunge into a repair. It just might save you a migraine later. Buy the manufacturer's shop manual for your vehicle, and read up on the repair. Check information online, such as the Maintenance Advice in this section or other resources.

Here's one true story of why it's important to do your homework:

When we first got involved in car repair, we once contemplated a job and took a quick look at the service manual. It had only six steps. We decided we'd go for it. So we went out and bought the parts. When we looked at the manual more closely, we noticed that the first step said "remove engine." No kidding.

So read the manual!

5. See one before you do one.

The best way to learn is to work with someone who knows what he or she is doing. If you're undertaking a repair you've never even seen done before, it's reasonably likely that you'll screw it up — or, at best, you'll do it the hard way. Our advice? Operate on the same principle that medical schools use: see one, do one, teach one.

6. Don't be ashamed to ask for help if you screw up.

It happens. You got your old serpentine belt off, the new one on ... and your car runs backward. Don't be shy about calling your regular mechanic. Our advice is to fess up immediately. Tell him you screwed up your repair and need a question or two answered. If he's a nice guy, he'll take pity on you and answer a question or two.

Don't take advantage of your mechanic, however. Remember that he's probably extremely busy trying to pay off his new 24-foot cabin cruiser.

A final word of advice. If you really screw up and have to take your car to your mechanic, don't try to cover it up. Confess. We can tell immediately when a customer has tried to hide a repair gone awry. Everyone makes mistakes, strips bolts and blows parts up. It happens. It may take a few years, but eventually even you'll laugh about it.

7. Safely dispose of the toxic crud that will come out of your car.
After you're done with your repair, it's possible you'll be left with used coolant, motor oil, brake fluid or other toxic materials. You'll need to dispose of them safely — and by that, we don't mean dumping it on your neighbor's award-winning Malaysian petunias.

If you ask nicely, your mechanic will likely accept your waste for a proper burial.