Question

I prefer working in Java, so, if there are any problem sets or questions in this area, I'd be glad to help.

Answer 1

not sure what you mean by problem sets but there are tons of sites dedicated to this kind of stuff

http://rosalind.info/problems/list-view/ is a biology based one. it apparently works best with python but I've done a few knowing only c++
http://projecteuler.net/problems has math problems
http://rosettacode.org/wiki/Category:Programming_Tasks various
https://github.com/karan/Projects-Solutions/blob/master/README.md various