A lot of women use FF that aren't actively TTC. FF can be picky about who it allows to sign up though. If you have any problems just PM me your e-mail addy and I'll send you an invite. A lot of women will also by the book "Taking Charge of Your Fertility" which comes with its own charting software. Many women here actually use TCOYF as their charting software and just use FF for the ticker. I don't use TCOYF, but I can't make out the charts to read them. It is highly recommended though.
As far as BBTs go just try to get one with memory for at least 1 temp and make sure it will beep when it's done. Some of them are fancier and will do things like light up, remember 10 temps, flex, etc. Mine is just a $10 one from Walmart.
OPKs are going to be more specfic to you. I use the ones from
www.accuratepregnancytests.com. They're just dip strips and very cheap. Since they're individually wrapped they last up to 2 years unlike Answer Dip Strips which are packed together and expire after 30 days. Some women have trouble with dip strips though and prefer midstream tests. Unless you use digital OPKs you will need to pay careful attention to the test line to know whether or not it's positive.
Remember when charting that you need to take your temp the same time every day after at least 3 hours of sleep. If you want to sleep in you can just wake up, take your temp, write it down or let your thermometer remember it, and go back to sleep. Even if you choose not to use FF as your charting software I recommend signing up for its free charting course. It e-mails you 1 short lesson every day and it is 20 lessons total. It can be very helpful.
Good luck!