I'm a light sleeper too and wake frequently at night. For me as long as I get about three hours of sleep I can temp whenever, but I still try to temp the same time everyday. I was able to BF throughout the night and still get accurate temps this way so... Also if you plan on using charting to prevent, FF isn't recommended. For one it's pretty inacurate as far as predicting ovulation. I hear women all the time saying how it changes their ovulation date. I use and like TCOYF as do a lot of long term charters. There is also other software out there like from the CCL (couple to couple league) and I think a few others. If you are NTNP then go ahead with FF.
Also I've noticed a lot of women who are ttc lately who might be having trouble with decerning EWCM and semen. I also recommend buying Taking Charge of Your Fertility. Although I've never read it, it seems to really help a lot of people.
Finally if you plan on seriousely using charting to avoid pregnancy, you might want to think about taking a class. Catholic or not, you can call a catholic church and ask them if they can refer you to a CCL course or NFP course. There are also some links to online courses where you can ask instructors questions. There are links for this on the NFP and FAM boards (as well as for some different software I think)