it's also worth checking the books and audio plays around Doctor Who... especially Lungbarrow, which deals with a lot of The Doctor's 'earlier days' on Gallifrey...
I won't say too much about the book, but it adds a whole lot more to The Doctor's character than you'd believe, and explains a lot about the way he views time and what the future / past holds for him...
673 years ago the Doctor left his family in that forgotten House. Abandoned, disgraced and resentful, they have waited. And now he's home at last. All is not well on Gallifrey however, the beleaguered Lady President, Romanadvoratrelundar, foresees one of the most tumultuous events in her planet history.
Trust me, if you can find a copy of this book, either in normal or e-book format, I highly recommend it for any Doctor Who fan who wants to learn more about The Doctor's origins / future