I am also a novice script writer, but before I began scripting bots I learned java for competitions. Object-oriented programming (OOP) is not something I focused on too deeply but I read about it and understand the concept. In my studies I use a few reference books like http://www.bluepelicanjava.com and Head FIrst Java http://www.headfirstlabs.com/books/hfjava/ The former is available for free download. The latter you may be able to check out at your local library (which is a valuable resource for finding java literature without having to pay) or purchase. If you're interested in how I'm learning the API and constructing my projects, you can add me on skype (inphantasmal). Good luck.
-DF