Howdy !
I'm not sure but your'e picture's seem to be of U-505 ?
A good reference book would be : Anatomy of the ship The typeVII U - boat byDavid westwood.
It's full of diagram's and a "Treasure trove" of other information. While your'e pictures are of a Type IX -C the book has a lot of information that crosses over to many type's of U - boat's.
Another book with a few diagrams in it : Type VII U-Boat's by Roger Chesneau. There are a few pictures in it as well.
And if you can find one I "Highly reccommend" this book :German Warships 1815-1945 Volume II U-Boat's and Mine Warfare Vessels by Erich Groner. I have used this book in my own research so much that it's now "dog eared" and full of note's in the side bar's.
Like I said before, much of this information is about the Type VII but many of the fitting's and part's crossed over to the other types of sub's.
Hope this help's and I will be following along as you progress.