T,
I understand your concerns. Starting to Work on your own car can be very challenging 'cause your always afraid that you're going break something that will cost a million dollars to fix or worse permanently wreck your engine. But you can do it. Changing you spark plugs is fairly simple (even on the V-6). The toughest part is just getting at the rear plugs cause its a tight space and hard to see. You might not do it this time, but if you go to a mechanic, find one that will let you observe what they do and will answer questions.
Either way:
First go get the Haynes manual from your local autoparts store or ebay. (15.00 at store, 10.00 or less on ebay). This is an indispensible resource for repair and just general information.
Next get together a basic tool set: SAE and Metric wrenches, 40 piece socket set, lg and small flat head and phillips head screwdrivers, and a couple of pliers. Finally a toolbox. Total Cost: 100.00 Other tools you'll buy as you need 'em. My first tool set was a $30 150pc plastic case set.
Next, read through the Haynes manual, just to get a feel for some stuff. Work on the basic maintanence items. This will let you get a feel for working on the car and help you identify different parts of you car. Reading the manual close enough and working through the various explainaton of how things work will give you a good idea of just how things work and why a problem causes certain results.
Finally, the hardest part is getting up the guts to turn that wrench. I started my master shade tree mechanic qualifications in college when going to the repairs shop wasn't an option (no $$$). I've changed brakes, oil, gas, and air filters, plugs/wires, installed stereo equipment, and bunches of other stuff (most recently cleaning the EGR passage to the throttle body - saved 100's of $$$)
And this place is Great for help on just about everything.
Good luck
