There are two files and two simple guides you need for filing. You need a round file the correct size the cutters and a flat file for filing the rakers.
The first tool is a filing jig to ensure you get the correct angle on the cutters when filing and ensure the angle is consistent on all the cutters (you can tell if your angles are messed up because the saw will not cut straight...it will curve as you cut).
The second tool is a depth gauge, which is used to set your rakers. (The cutters cut the wood, the rakers "sweep" the chips out of the cut) As you file the cutters, they get slightly "shorter" each time. The rakers are designed to sit slightly below the cutters, so as the cutters get shorter the rakers get higher relative to the cutters and the saw will start to cut very slowly or not at all (because the rakers are preventing the cutters from touching the wood). So, every few times you file the cutters (unless you take a lot of steel off during a filing, in which case you will have to file the rakers more frequently) you have to file the rakers. The depth gauge is used to make sure you get the right depth....enough, but not too much (if you take too much off the rakers the saw will take to big a bite and bog down).
The guides are not complicated and are very simple to use. As with every thing else, practice makes perfect. The good thing is its really tough to permanently screw up a chain, so if you try and it doesn't cut like you want it to, try touching it up again. Here's a link that talks about terminology and mechanics of the chain.
Oregon Chain FAQ's
There are different types of chain, usually referring to the number of cutters...."anti-skip" (which is supposed to help prevent kick-back, "skip tooth", "full comp". Most saws come new with anti-skip chain. There are also different types of cutters (which determine how they are filed)... there is round tooth (most common) and chisel tooth. Also, using a grinder to file is good if you are a professional, but the cost of the equipment and time it takes to learn to use it out-weigh the benefits for most people. Also, once you grind a chain, you must continue using a grinder because it changes the cutting edge on the tooth (ie, you can't go back to hand filing).
My advice...go to Bailey's or your local saw shop, get a filing jig, depth gauge, round file, and a flat file and start making metal shavings. /ubbthreads/images/graemlins/grinning-smiley-003.gif And to answer your original question, I use regular old Oregon full comp.