Okay, first off you need to be looking at the pistils, or hairs, on the buds. when you see about 70% of them change from white or amberish color to orange, red, brown or whatever; that's when you cut them. thus "harvesting"

After you cut them at the bottom of the stem, you want to cure them. to do so, hang them upside down in a closet or something, where you can control the air by closing it off, keep the door mostly shut for a day and them move it out a bit each day. after like a few days of that, you might want to cut the branches from the stem and hang them in a cardboard box until dry.

*note* cut them either earlier-for a more cerebral high- or a little later-for the couch lock effect high.