How to track ovulation

[Chamonix1]

I didn't bother before when we conceived dd but with husband working very very long hours it would be good to know when's best to dtd. So tracking ovulation for dummies, how do you do it? Just ordered a thermometer and opks off amazon, what next?

I started with opks this month and started testing a few days before I expected ovulation. I had no second line at first then suddenly feint line then later that day almost positive, followed by positive the next morning. My peak was a couple of days later than I had expected it. Ovulation is meant to be 12-36 hours after peak. HTH