Depending on where you live, you might be able to qualify for hormonal contraceptives from a free clinic and often times these places charge on a sliding scale or provide them for free. I know several people who are using Depo-Provera without cost from a clinic in my area (of course, Depo-Provera might be risky if you're a depression sufferer, since hormonal contraceptives can increase/cause depression and while you can stop taking a pill and be fine, if you get a shot, you're stuck for three months).

The other options are good though condoms, spermicide and proper lubrication either natural or water based (if not friction/breakage). Condoms are pretty effective when used properly. If anything goes wrong, you can get Plan B (the morning after pill). Depending on where you are and how old you are, you might have to go to a clinic. Here it's behind the counter at the pharmacy, you just have to ask for it.