This page is intended as a reference for making your own patch cables and crossover cables. To do this you'll need a length of cat-5 / RJ-45 cable (buy a 500' spool, very cost-effective), an RJ-45 crimper ($15-$30), and some caps.
You use a patch cable (where both ends have the same wiring) to connect a computer to a hub or to a wall jack. You use a crossover cable (where certain wires are crossed, so that the two ends are different) to connect two computers directly. If you make a crossover cable, mark it as such. You don't want to get confused later.
The maximum length of a cat5 cable is 100 meters, or 328 feet. Don't make it any longer, or you'll be sorry.
To begin: remove the first inch of outer casing. There is some fibrous stuff inside; either trim it or move it out of the way. Next, holding the cable so that the individual wires are pointing up and away from you, line them up.
For a patch cable:
Line up the wires this way for both ends of a patch cable, or one end of a crossover cable. It goes: Orange-White, Orange, Green-White, Blue, Blue-White, Green, Brown-White, Brown.
For a 100baseT crossover cable:
For a 100baseT crossover cable, do one end as described above, and the other end this way. It goes: Green-White, Green, Orange-White, Brown, Brown-White, Orange, Blue-White, Blue.
crimping the cable
Flatten the wires out, trim the ends neatly, and slide them into the cap. Put the cap into the appropriate hole in the crimper, and squeeze. Your cable is done; make sure that the wires are still lined up properly and that the pointy bits have penetrated the wires. Test the cable to be sure it works.