Actually I don't recommend that one from the research I've done. If you read Hadley's 'Count Not the Dead' there was a scathing remark about that book by a U-Boat historian (don't remember the name off-hand). But it isn't a recommended book. This is even discussed on uboat.net
'Steel Boat - Iron Hearts' by Goebler is a very good one (it is not from the perspective of a commander)
'Enemy Submarine' by Wolfgang Frank is another good one. Frank went out on a patrol with Prien (much like Buchheim did with U 96). There are some minor inaccuracies in the start of the book, but that is the only 'first hand' account that I could find of someone who went out on patrol with Prien and wrote about it.
There's a start though...I can dig up others.
fftopic:
Prien, have you got Ken Wynn's two volumes on U-boat ops?
I might be a touch biased as I know Ken but they are spectacular. Ken went and lived in Germany for about 6 years to research and write them. They are a tour de force and contain tremendous amount of info on individual boats, crew members, patrol details, etc, etc.
Must have if you're into U-boat history.