You may want to start with learning about enterprise level databases. Like kas said, OOP is the "here and now" of programming. A great way to get yourself into a mindset of building objects and desiging systems is to start at the core; the database. After you get into table relationships and normilization, it's a wonderful jump off point into any OOP language.

It's easy to get started in, but takes alot of trial and error to master.