Okay, hops are an interesting beast, I'll give you three versions, first when a hop comes to you:
You and the hoppee (let's use when Bittersweet Seraphim is coming out, I'll do a hop) I would contact you and ask for you to post something I've come up with, such as an article, a character interview, a giveaway, etc. You would set up your blog post with my info, maybe include an intro and make sure it goes up on the right date and time.
Let's say you are the hopper! This part is a ton of work. You contact bloggers, authors (you are always welcome at my blog BTW) and ask if they would be interested in hosting you. You compile a list and create a post to send to each stop with clear instructions on what they need to do and when. This information should have an blog hop banner if you can whip one up, or have one made. Then one the day they post, you have to get back and comment as best you can.
Now the last type is joining an already existing hop. Usually hosted by a few bloggers with a grand prize, until you get the hang of the hops, avoid the ones that charge money. Read the instructions carefully and make sure to sign up on time and make the required post on the right day. If you check out the side of my blog you can see I have two lined up: http://debraanastasia.
and here is where I signed up so you can get an idea of what they look like: http://riverinaromantics.
Can anyone else think of something to add?