I will be talking about the Android framework next week. If you have an interest in exploring the examples I will present next week or if you are thinking about doing a semester project using the Android framework, then you need to get a version of Android installed on one of your computers. I wrote up a post last Spring called Installing Android that covers the basic steps. Note: I make references to "API 9" in that article. That version is now out-of-date. You should instead simply install the latest version of Android that is available.
In addition, here are some pointers to additional resources that you may find useful in helping you get up the learning curve on Android.