Good choice, Wildspear, I have both, they're outstanding.
Three others, that I'd recommend, and are still available are:
1) Osprey's, New Vanguard, "US Submarines 1941-45" by Jim Christley.
2) "U.S.S. Cod, WWII Submarine Memorial" from Oxford Press.
3) "Fleet Submarines of World War Two" from Floating Drydock
Lots of great detail info.
Three more, worth having, but out of print, are:
1) "Profile Warship #34 USS Barb (SS-220)" from Profile publications
2) "U.S.Subs in action" Warships No. 2. The old one from Squadron. Still good
3) Leeward Publication's "Ship's Data 5 USS Bowfin (SS287)
IF you can find any of them, and they're not too expensive, grab them.
Lastly, keep and eye on Periscope Film's site. They already released "The fleet Submarine" (which I swear by), and there are more in the pipe line. Also checkout their DVDs. Some of those movies, I haven't seen since the late 60s - early 70s, and others, never. AND, unlike what we see on TV, most of the reproductions are as clear as the originals. They must have some kind of filter-software, that cleans them up, a bit.
And remember, good books and reference material, beats all the experience in world, when it's coupled to an old memory. Most people forget, more than they ever learn.
Green Board and DBF,
Mike K.