Not sure where you live but here in MA hops can usually be picked late August/early Sept. I used to have very mature plants at my old house but moved three years ago and my new plants here are just beginning to "grow up" and yield lots of cones. I'd pick them when they have grown large in size but just before the cones start to show signs of browning. I have cones on the vine now that are very brown (I decided to leave them on and not use them due to low yield) and the hop glands on the inside are still very fresh smelling when crushed in your hand. I'd not use these, but frankly, if you pick them early or late and you think they are fresh enough...use em. There are plenty of articles on the web as well.
Cut them to the ground and cover with ash and good compost for the winter...cut down all but the best 5 or 6 shoots from each plant in the spring when the first appear and you should be very happy with yield by August/Sept. Good luck!
Oh yea, regarding drying...I've used a food dehydrator...or you can stick them on a sheet pan and in the oven at low heat, or leave in a paper bag in a cool dry place to dry naturally. Vacuum seal and freeze when dry.