Here I'll just assume that you've smoked weed before, or you probably wouldn't have started growing yourself.
Well, it's entirely up to you when to harvest, depending on what kind of high your prefer. For instance, You'll get an energetic high with more "milky" trichomes, while you'll get a stoned high with more amber. Tho, it's also a little depending on the plant how much amber is needed for the stoned high.
- Harvesting with a lot of clear trichomes, should be avoided tho, since they don't really contain any THC. so you'll just have wasted your time caring for the plant, if your intent is getting high off of it..
Personally, I prefer a stoned high, so I wait longer than most people before harvest.