The Guide section is under the Support thread - then just look in Technical Development to see the current projects that are being worked on. Members usually help out anyway with links or news or discussion, or comment on developments.
We are also developing a task based system for forum tasks where you can assist in one off or cyclic tasks on the forum. See Crowd sourcing to get involved in that…
You can also volunteer as a member of Staff, which entails getting involved for a couple of hours a week to spread the work involved in tasks, such as, greeting new members or helping in the Language forums or Support on the forum. PM Ruthie if you want to get more involved in that.
So … Re What to study.
I think the mobile wallet is the hottest development at the moment, I wish I had time to get involved in that. It covers all development areas + its mobile. I just posted a stub project for porting that to Samsungs new Tizen (open source) Android competitor / operating system.