First things first, go to couchsurfing.org, and set up your profile. Fill it out as completely as you're willing to, and go ahead and be a little quirky about it if you like. Memorable and interesting people have a much easier time finding hosts. Make sure you upload a recent picture.
Next, get your profile verified. This means locking your address into the system, getting your postcard, and entering in the validation code. I also suggest donating to complete the verification process, but that's a personal decision.
You're almost ready. Here's the most involved step. It will take a little time and help to do, but I highly recommended it if you want' to find a host: get another couch surfer to write you a reference. The best way to do this is to find a friend who already knows you and is on couchsurfing.org. (Seriously, if you're someone who I know well, and you want a reference, email me with your profile address and I'll write one for you). Post a status on Twitter or Facebook saying you've just joined and want to know if anyone else you know is involved. You'd be surprised which of your friends and family might respond. If it's an especially close friend or family member who has more than three vouches, they might vouch for you (don't ask for this though, it's not polite).
If you really don't know any other couchsurfers, it's time to go out and meet a few. Go to the community tab of the website, and search both events and group for your hometown. Then go out and meet the surfers. You'll have a good time, and you'll make some friends on the site, who can then, if you hit it off, write a reference for you.
Once you've got a completed profile with picture, verification, a good positive reference, you're ready to start looking for a couches.
A good time in advance (a week or more before your arrival date, if possible), start searching for a host. Hit the Surf/Host Tab and hit Couchsearch. Enter in the location you're going to surf (and if you feel like it, some qualifications about gender, age, interests etc) and you'll get a list of hosts. from this list, you are going to choose several to message, asking to stay on their couch.
One trick, before reading profiles: I like to sort the search results by "last login date." The surfers who appear at the top are probably the most active hosts who log in the most often and check their messages. They're often sent fewer couch requests than the people who show up at the top by default, and are more likely to respond to you.
Here are the things to look for:
-Do they appear trustworthy? What do their references say? Do they have a picture on their profile? Have they been vouched for/verified?
-Do they like where they live? After safety, I consider this the most important thing to look for. A host who is passionate about their home can make your stay absolutely incredible. A host that hates where they live will not.
-Do they speak your language? All users list the language(s) they speak and rank them in terms of proficiency. Their grasp of English of course is usually evident from what they've written on their profile.
-Where in town do they live? Is it somewhere you want to stay? Is it safe? Convenient?
-What's their "couch" like? Do they smoke? Have pets? Are you going to be on the floor or in a spare bedroom of your own? Most profiles will have pictures and all will have a description of their "couch" and their house rules (if any).
-Does this look like someone you would want to spend time with? Do you have interests in common? Do like to party as much/little as you? Did you study the same things, or are you pursuing similar careers?
Once you've picked out a few of your favorites, it's time to start sending them request. As a surfer, nobody minds if you message more than one person. I usually send requests to 5-10 people every time I want to couchsurf. However, quality of request is far more likely to get you a place than quantity. Here's how:
Read your potential host's profile carefully, and then in your first message to them write something that makes it obvious that you read their profile.
This is the most important thing you can do when requesting a couch. Hosts like knowing that a surfer has chosen to write to them for a reason. Even if I copy/paste a request message to several people, I always include at least one sentence specific to each host showing that I read their profile, know who they are, and actually want to meet them.
After that... just wait. You should get responses soon.
Or not. There's one other trick you can use for major cities. Under the community tab, click search group, and then search for your destination city. You'll find a message board for surfers in that city. Go to their group's message board and look for something along the lines of "emergency/last minute couch request group." Drop them a message there. If you're lucky and have a good profile, you might find a host that way. But make sure you read your potential host's profile carefully before accepting.
And that should get you on your way to surfing your first couch. Best of luck! Stay tuned for tips on getting started as a couchsurfing host.