Forum:Where Can You Find What Happens After Book 7?

Ok, i'm a little confused. Ok I've read all seven books and the last one leaves a few unanswered question BUT a lot of us seem to know the answers to these questions such as

Q: Who killed Lupin? A: Antonin Dolohov

Q: Who killed N. Tonks? A: Bellatrix Lestrange

Q Does harry ever become an Auror? A: Yes

But these answers were never given in the book so WHERE did we get them? Is there a source by JK Rowling telling us all this? Did she ever write an encyclopedia giving us this information?

I really want to know more about the NEXT GENERATION where do I get this information?