Hi! The first thing you need to chart is a BBT thermometer. You can't use a regular thermometer for reliable charting. You can find BBT thermometers in the drug store near the pregnancy tests, or on Amazon (amongst other places). Then, make sure to sign up for Fertility Friend or a similar site where you can enter your temperature every day. It's important to take your temperature at the same time every day, and do so after at least 3 hours of uninterrupted sleep. Take it before getting out of bed, drinking anything, or even talking, as these can alter the reliability of your temperature.
There are a lot of benefits to temping. For me, the biggest ones are confirming that I actually am ovulating (even OPKs don't confirm this) and identifying how long my luteal phase is each month. It's only through temping that I've discovered a problem with my luteal phase.
Good luck!!