There are so many ways to enjoy hops whether fresh or dried. Fresh or Wet hops are discussed in this Instructable.
Step 1: How to Know When Your Hops Are Ready to Harvest
Native to Europe, Asia and North America- hops now grow on many continents and in many countries. In the Pacific NW many feral Cascade hop plants can be found growing on telephone poles, shared fences etc. Please always be courteous to the people that grow or cultivate hops and ask them before you harvest hops about town unless it is clear that they are truly "wild" plants.
I grow many different varietals of hops (they are all the same species, just different cultivated varietals, just like wine grapes) in my own yard and have many friends that grow them for the pleasant shade they provide when allowed to grow on pergolas and fences. It takes about two years to have a crop of hop flowers large enough to make a batch or two of homebrewed beer from, but after that the plants can be very prolific growers and producers. About this time of year I end up with a large hop harvest from my own hops (Cascade, Galena, Golding, Sterling, Willamette and Zeus) and extra Cascade from my neighbors. To know that the hops are ready to be harvested, they should be fully grown (more than an inch long for most varietals) and the blades or petals of the cone should be a little bit papery. Some of the hops may already have some browning on the tips. They are not ready if they are very springy and wet feeling, they are over-ready if they have opened up into full bloom and have turned yellow/brown. Please wear gloves that go as far up your wrists as possible when picking hops or pulling down bines because they cause "hop-rash." They seriously do, and it's no fun.
Step 2: Harvest Those Hops!
Get a good helper like I did and fill some paper bags with fresh hops-
Then get them in the fridge or in your brewing beer asap!
Step 3: Dry Hopping With Wet Hops
Well... this certainly sounds like an oxymoron.
Fresh hops right off of the bine (yes, bine- not vine) must be used quickly or they will start to mold or go all cheesy and gross-tasting due to the oxidation of the oils in the hops. They are called both "Fresh Hops" and "Wet Hops" interchangeably.
Using wet hops or fresh hops is super fun and makes for some amazingly floral beers, but if you've got more than you can use in a harvest, don't throw them away, see my other instructable for building a Hop Drying Oast.
Step 4: Dry Hopping or Adding to Boil
Let's talk about avoiding bacteria or wild yeast infection a bit-
Depending on where you are with your brewing process you can either:
1. Add the fresh hops into the boil of a new batch of beer to make it a fresh hop beer. In this method the boil kills the bad bugs you don't want infecting your beer.
2. Add the fresh hops to the secondary fermentation vessel (in this case a glass carboy) after the vigorous primary fermentation stage and enough alcohol and CO2 has been created to kill the nasty bugs you don't want in your beer.
3. Add them into a filter cartridge or what is called a Randall between your keg's output line and the tap
Many people add fresh or wet hops to other stages of beer making like after flame-out as a steeped hop addition for aromatics, but try at your own risk of spoilage :)