Need help: connecting wires to a fuse box

Hi all.. i'll make this short and simple..

I am a total newbie when it comes to wiring and anything electronic with cars, but I need a fairly detailed way(.. or atleast something that makes sense... ) of running a wire to a fuse box. I need to connect one lead wire to a 12v source to power some lights (added accesory), and the box tells me to use 'parking lights, high beams, etc. etc.'.. but ive been told a better way is to use the fuse box..

only problem is.. i dont know how

how exactly would i go about connecting a wire to a 12v / 10a fuse/unused fuse properly and safely. Please.. any and all help (including pics!) would be EXTREMELY appreciated

the car is a 1992 toyota tercel, but i guess just general help is all i request..

thank you in advance!

Carlos

ok, this isn't as hard and confusing as you think. (i will try and include pictures if i can find any on the net).
Let me first give you a breif electronics lesson:
electricity in a car travels one direction, from the positive side of your battery (and alternator) to the body of the car. which means that anything you want to hook up needs to get power then have a ground wire to the body or other metal (almost every peice of metal in your car is negatively charged at 12v). Not sure if this was necessary but it may help give you a picture of exactly what is going on.
Now for the actual wiring. first find your fuse box (either underhood or in the passanger area). then locate the headlight fuse. use the following table to determine exactly what you want these lights to do and how to wire them:

only on when low beamss are on----------low-beam fuse (either side)
only on when high beams are on----------high beam fuse (either side)
on whenever headlights are on------------parking lights fuse

find the fuse that meets your needs. now comes the tricky part. you will have 2 options here, you can use the fuse that you are tapping off of to keep your lights safe (cleaner install but more likely to blow the fuse and a bit more difficult to figure out) or you can just tap the fuse and put an inline fuse on your power line.
To tap the fuse you will need to go to radio shack and buy fuse taps there stock number is 27-1204 and they are $1.29. you can see one here (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F010%5F015%5F007%5F000&product%5Fid=27%2D1204) . you will also need Quick-Connect plugs to put on the end of the wire so it can connect to the tap. make sure to get the right size for your wire and the tap size. you can see what they look like here (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F005%5F003%5F005%5F000&product%5Fid=64%2D4040) .
now, cut off any connector that may already be on the power wire you are connecting and crimp on one of the connectors you bought. then pull the fuse you are going to tap and connect the tap to it and reinsert. now attach the power wire to the tap and ta-da! you have taped your fuse box. Make sure you have an inline fuse on that power wire, there already should be one but just double check. if you have any other questions i would be happy to help answer them. good luck

wow! thanks for the help.. it worked almost perfectly.. except:

Now when i plug the wire into the wiretap harness thingie, the lights are always on. Even when the key is removed, lights are off, doors are closed, no ones in the car.. theyre still on

there were 2, 10A fuses in the box in the engine compartment.. one is for "HEAD LH" and "HEAD RH". I assume thats the left and right headlamps.. i tried the tap on each.. on either side of the fuse prongs, also, and still the same result. What should i do?

I tried to tap a 10A fuse for something labeled "TURN" (turn signals?) inside the car, under the steering wheel.. but it was too difficult to insert the fuse back w/ the tap, it wouldnt fit.. can i open the slit a bit more to assist in that? perhaps that one will work better?

once again thanks for the help thus far..

Carlos