I recently read Ray Monk's excellent biography of Wittgenstein, and would like to read something by the Austrian philosopher himself. It seems that you need to know a fair amount of logic to start with. I've taken college philosophy classes before (including logic), but they seem too easy and are not much of help here. So what are some texts you would recommend to study before reading Wittgenstein? Thanks!
Edit: I'm not confining the scope to logic books only. I thought that was the part I didn't understand, but it could very possibly be wrong. Also, if possible, could you recommend books that do not directly concern Wittgenstein but will be helpful?