Functioning of BRCA2
I'm just skimming through it now, but this 2011 review in Nature Reviews Cancer looks like it has everything you could possibly want to know about the BRCA1/BRCA2 pathway. If you don't have access to the journal, the first page of this Google search should have a PDF link to Researchgate down near the bottom, or you can try this direct link.

I apologize for the "link-only" answer, but there is a ton of info in the paper, and it would be rather difficult to summarize it in just a few paragraphs. This is a rather broad question, so perhaps you could read through the review and references, and if you still have specific questions about the pathways or interactions you can ask another question.