We started keeping a log of who shows up in a notebook. We just start a new page every meeting. Nobody really told me why though. I just sign in.
As for your software, for simplicity, I would just go for a web based thing. It's easy to deploy and I think it would be easier to develop. Of course, depending on how much control you have over your server, you might not be able to keep people from cheating by signing in at home.
If you really want an application, I recently started using Qt (
http://www.trolltech.com). I use linux, so my only choices were Qt and GTK+. Both are cross platform (but I think GTK+ doesn't work on Mac). The reason I chose Qt was that it has a nice utility for making GUIs. Making the interface is essentially drag and drop. Make a window, then drag buttons into it. Then you just connect each button to a function. It's only for C++ though. GTK+ has bindings for other languages. I think VB has a utility similar to the Qt one. But Qt is free and VB is Microsoft...
Your other option is to learn the Windows API in the language of your choice. Just remember that GUI programming from scratch is messy. There's lots of strange classes and function calls floating around. I've learned enough about Qt that I could probably write something from scratch, but it's too big and messy for my tastes.