Confused about when to harvest (BUDS)

Hello, i started out with three plants dec 2/04 and one i have dried and smoked and it's nice/mellow but sometimes i get a headache. The other two plants still have white hairs not amber or golden brown yet. When or how do i know when to harvest? I would like to start my next grow soon (sea of green)
Also the first plant that i cut i let dry for about a week then i put the buds in a mason jar for about 10 days opening each day to let some are in. These were golden brown hairs on all so i cut dried and smoke. Not too bad for bag weed. What are trichromes?
Thanks for any advice

There is a FAQ at the other site, OG, called trichrome 101. you might want to read that since an explanation can get rather lengthy. But trikes are the best way to tell when a plant is ready to harvest and it is well worth your time to check into the facts. here is a pic of some trikes i took some time ago.

Thank You Sativus i will check into OG And Let You know!