You also want to make sure that you aren't running the cable parallel with any power cables/wires. Doing so for more than a few linear feet can cause some interesting errors.
Also, make sure that the cable isn't kinked or coiled up with itself. Cat5/Cat5e cables carrying signal are much more likely to cause crosstalk with themselves than each other (in typical network installs I put 300+ cables running for 50+ feet in the same conduit). However, if you're like many people and you buy the Cat5 from best buy, it comes coiled up fairly tightly. When many people unwrap them, they don't always unwind them, just plugging the two ends into computers a few feet apart. This causes havoc as you then have anywhere between 10 and 50 feet of cable coiled up together.
If you want to eliminate collisions, you will need to purchase a switch (not a hub) and make sure it and your network cards are capable of "full duplex" operation (i.e. capable of talking and listening at the same time). There is no such thing as a collision on a full-duplex circuit.