The great thing about the MSF Basic RiderCourse is that it takes you from knowing nothing about how to ride a motorcycle and teaches you everything you how to ride. You can get ahead of the game, though, by doing a little homework before you take the class. MCrider shares some tips to help you prepare for your class.
Read The Friendly Manual
During the classroom part of the course, you'll go over the Rider Handbook in detail. This handbook is available online for free on the MSF website. There are no surprises here. What you see is what you'll go over in class, and what they'll test you on. You don't need to memorize the book before you go, but becoming familiar with the material ahead of time can help.
Practice On A Bicycle
If you haven't ridden a bicycle in 20 years, zipping around on one can help you get familiar with being on two wheels again before you hop on the class bikes. If you're ambitious, you can even practice techniques like countersteering and choosing the proper line through a turn. Personally, my own experience doesn't agree with this tip. I raced bicycles before getting into motorcycles, and I didn't find that my years on bikes without motors helped me ride bikes that have engines. That's just me, though. I do ride larger, heavier bikes than the 125s and 250s you ride in the class, so the experience is closer with the smaller bikes. The old Honda CM250 Custom I had for a summer felt like a bicycle around town compared to many of my other motorcycles. Others have said that bicycle practice before their motorcycle class helped them, and I'm not going to tell you they're wrong. I say use all the tools in the toolbox.
The Class Is A Learning Experience, Not A Pass/Fail
Yes, if you pass the test at the end of the class, you will get your motorcycle license in many states. Don't get too hung up on that, though. The purpose of the class is to teach you how to ride and control a motorcycle safely. Focus on the learning process rather than passing the test, and you'll learn more. If you do fail the test, often you can return at the end of another class and take the test again. Worst case, you'll have to take the entire class over again, but that will give you twice as much practice to get it right. People learn at different speeds, and we're not Klingons, so you will not dishonor your family for generations to come by not passing the first time.
Learn The Controls
This is one aspect I went out of my way to learn before walking into my class. I had plenty of experience in cars, but I had no idea where the corresponding controls were on a motorcycle. Almost any motorcycle made since the 1970s will have the basic controls in the same place: throttle and front brake at your right hand, clutch at your left hand, gearshift at your left foot, and rear brake at your right foot. Don't worry about secondary controls like turn signals, since these vary from one bike to another (Harley-Davidson vs. everything else, for example). If you have access to an actual motorcycle, you can sit on it with the engine off and practice finding these controls.
Be Smooth On The Controls
My biggest problem when my high school buddy taught me to drive his Chevy S-10 pickup with a manual transmission was releasing the clutch too abruptly. I stalled the engine almost every time. It takes practice to learn just how slowly and smoothly to operate the controls, not just the clutch but also the brakes, throttle, etc. Again, if you can sit on a motorcycle with the engine off (that might make your friends more willing to let you), you can practice this to a certain extent to help build your muscle memory. If there's no way you can do this ahead of your class, though, don't worry about it. One of the first things you'll do in class is learning this by "power walking" the bike across the range.