I started charting only in January this year. I use Fertility friend to help me chart my cycle. What is great about this site is that when you join they send you an e-mail everyday to explain fertility and how you could fall pregnant by understanding your bodies signals. It is free of charge except if you want the VIP package (which is not necessary at all). You can download it for your smarthpone/Ipad as well.
What you need is Basal thermometer that shows 4 digits, for ex 36. 32 and not just 36.3. However if you only have a glass thermometer that will do although it frustrated me that it took so long to read and with the digital one it beeps when it is finished as with the glass one you are not always sure if the final temperature was reached. Here is a website that stocks them:
It is important to take your temperature about the same time every morning after at least 3 hours of consecutive sleep before getting out of bed. You should only stick your arm out to get the thermometer to take the reading as movement affects the reading.
When you study the temperature fluctuations it will show when ovulation happened, but know that it only is evident 3 days past ovulation and only gives you an indication when ovulation happened. I would suggest you google further instructions about charting!
In conjunction with this you can also use ovulation tests. They determine the LH surge that happens before ovulation. The downside is that the tests are expensive if you use them every month, around R25 per test.
Then you can also purchase a saliva ovulation predictor microscope. This is my favourite toy (once I figured out how it works)!! You can buy it from Dischem for around R330. I wouldn't say this is essential but surely fun!