I plan on buying a motorcycle some time in the near but not too near future. By which I mean, not in the next month or two but within the year. Problem is, I don't feel like I know enough about motorcycles to make a good decision. I want a cruiser for riding around around town and occasional road trips. Something like a Shadow or a Rebel and I'd like to keep it cheap.

Any tips?

Also, Triumphs look totally fucking sweet, for what it's worth.

Believe me, I plan on being as safe as possible. I've heard a million and one horror stories about motorcycle wrecks and don't plan on being the million and second.
Also, I have no desire to own a Harley or anything that looks like one. (Although I saw a pretty sweet one last month that would almost make me change my mind.) Triumphs are cool but at the moment I'm leaning towards Honda.

I have ridden for a couple of years now, and still have my first bike.  

Depending on where you're located ye might be able to take a riding course to get your license - this would circumvent the test at the DMV.  It is available in my state (OR), though I don't know if it is so elsewhere.  It's normally a three day practicum with a certain amount of in-class instruction, with the rest of the teaching done on motorcycles (all 250's) - not on the streets of course, normally in a huge parking lot.  They teach students everything one might be tested on at the DMV: slow turns, stopping, swerving, running the motorcycle barrels, etc - along with everything practical from turning on the motorcycle to the proper way to change lanes (SMOG - signal, check the mirror, over the shoulder and GO).  

If that type of course is not available, a safety course is something I would recommend, as it can lower your insurance rate and also teach you useful skills if it is a practicum-style class.

Craigslist is honestly a good place to find bikes - learn what kind of bike you want (or a few different types), what the specs indicate when reading ads and what the average price for a used ______ should be.  You can get the idea of many of these by looking through the ads for a week or so - all the Honda Rebels, for example.  It's an easy way to learn what you might be looking for and what would best fit you in terms of price and all that jazz.  

Also, a used bike for your first bike is... a very good idea, if I may say.  There is a good chance you will do something in the first year of riding - lay it down, scratch it up just a tiny bit, etc - and buying a shiny new bike only to lay it down three months later is... disheartening.  

To pile on the suggestions:
1: Agreed on the 'don't ride without proper protective gear' - I'm still stunned by the mo-rons when I travel back to Malk's neck of the woods who will ride around without helmets, let alone a good armored jacket, pants, and boots. Just because it's legal.... But, I guess we do need more organ donors.
2: http://nm.msf-usa.org/msf/ridercourses.aspx?pagename=RiderCourse+Info - Motorcycle Safety Foundation RiderCourse - it'll likely let you bypass the driving part of the license test, and can get you a discount on insurance.
3: Keep your head on a swivel, and ride like they're out to get you... Because especially when they aren't paying attention, they're out to get you.

Agreed on the Rebel being a good, basic bike, and a good starter - I really like the Triumph Thunderbird, and if you maintain them yourself, older BMWs can be excellent - it depends on what your budget is, and what you're looking for. You might start with something really basic, inexpensive, and reliable that you wouldn't feel terrible about if you dropped it at a stoplight...

If you're looking for an online forum, I like the ones at http://advrider.com/forums/.