How should I harvest?

It depends on your drying area. I find that hanging the whole plant in one (just fan leaves removed) slows down the drying period slightly. But this is a good thing, you want it to dry slowly. Cutting everything smaller will increase surface area to the air and remove a lot of stems, which contain water themselves, so it'll speed up the process - good if you're in a hurry. Cannabis expert Ed Rosenthal recommends hanging the whole plant in his book about cannabis harvesting. I've done that and used a net drier (due to a lack of space), and the end result was definitely better from hanging the whole plants. I've also hung individual branches from pegs, but still found the whole plant dried that little bit slower and more evenly. But all these techniques will work with no problems. You can only work with the space and time you have, so do what's best for you. Enjoy the final weeks!