If you're a man this will probably be TMI, so consider yourself warned!
Last year I read the book "Taking Charge of Your Fertility" by Toni Weschler. It was an amazing read. It's crazy how many things about my body that I did not know! They don't get this detailed in sex ed. in school. This book talks a lot about the Fertility Awareness Method of birth control/conception, depending on the results you're wanting. Anyways, I couldn't really put it to use much as I didn't really have AF until very recently. The author includes a free software trial with the book. I downloaded the software and it really does make life easy, but the trial is only for 15 days and the software is $40 to purchase. Soooo I started asking around and looking around online and lo and behold I found what I needed for free.
Fertility Friend Website
The focus of this site is on conception as opposed to pregnancy prevention. I'm currently preventing, but it's still easy to apply the site for myself. Anyways, I just thought that anyone who uses the Fertility Awareness Method should be aware of this site. It's very easy to use. I'm sure tracking it by hand is easy once you get the hang of it, but I just didn't want to have to do that. And now I don't have to. I find it very easy to use. They also have tutorials on the site for those who want to learn about FAM. I haven't done the tutorials yet as the book I read was a very great introduction. But for someone not familiar with FAM and not wanting to buy Toni's book, I'm sure that this would be a great opportunity to learn for free. I do like the book because there's pictures that help to cement the learning. I don't know if the tutorial does this or not. I haven't bothered to look. At some point I may get around to skimming the tutorials at least. Anyways, enjoy!