It depends on how broad or narrow the focus of your paper is going to be.
Blair's
Silent Victory is pretty much
the benchmark overview history. Best single source for a broad description of the sub service in World War II. Roscoe's
U.S. Submarine Operations in World War II is also a good overall study, but it's older and (depending on your library) not quite as readily available. You can get it at Amazon (along with Blair), but I think it's only in hardcover and is not cheap. It is still well worth a read, though, especially if you're looking for something to compare and contrast with Blair. It's not that they take opposite points of view, but rather that they wrote in different eras with some differences in their perspectives as a result.
Another good authoritative history (of the Pacific war in general) is S.E. Morison's
The Two-Ocean War. It is a summary of his 15-volume official history of the Navy in World War II. Morison is a little dated too, now, and of course he's not specifically focused on subs, but if you have the time to include it in your research, it's an excellent way to view the sub service within the context of "the rest of the war."
If you want techincal info on subs,
The Fleet Type Submarine (see the link in remelend's post) is the only way to go, in my opinion. It's a primary resource, though, without any narration to guide the reader to a boiled-down, ready for an English paper conclusion. You could also use Norman Friedman's
U.S. Submarines Through 1945 to get technical info, but I personally find it a very difficult read. It is extremely interesting material presented in a most uncompelling, cloying sort of way. But nevertheless full of good information and it might help you if you need clarification about things you find in
Fleet Type.
Lastly, I think James F. Calvert's
Silent Running is an excellent and readable personal account. I single out Calvert every time I recommend a sub book because I personally admire his ability to remain almost journalistic in his narrative - without second-guessing through the benefit of hindsight. Blair can get a little peppery at times, I think. Other than Calvert, I would not read too many personal accounts of the sub service. It's not that they aren't worth reading - they are - but for the purposes of a first year English paper I think you'd end up spending a lot of time reading them for relatively little unique information in return.
Anyway, bottom line - if I had to choose just 3 of these, they would be:
Blair, Clay Jr.
Silent Victory
Morison, S.E.
Two-Ocean War
Calvert, James F.
Silent Running
And of course, the best source for info is here - Subsim! Think you could get away with citing it in the bibliography?
Best of luck with your paper!
Cheers,
Rob (former English major and current history geek)
[Edit - Forgot to mention one other book,
Back from the Deep: The Strange Story of the Sister Subs Squalus and Sculpin, by Carl LaVO. In particular some of the early chapters deal with the training of enlisted men (whereas the other books I mentioned focus more on an officer's perspective). It's a quick read, too.]