It has drawings (not plans - you would need to have craftsmen available to you in any case and they could probably build the things from drawings) of various types of building and energy production stuff.

There are chapters on weapons, of course, and how various types of weapons affected warfare, including a lot of stuff on ship-to-ship combat, how to get more than one row of oars onto a boat, and how to plot a course to ram another boat, much of which would be completely worthless. The Romans designed a boat powered by a water wheel driven by two oxen in the hold walking in a circle, though there's no evidence they ever actually built one, and you probably wouldn't want to. The stuff about bows and arrows probably not so worthless, though the discussion of sinew rope, which was used as cordage (made very good bowstrings compared to other primitive materials) and apparently no one knows how to make anymore might be frustrating once your society runs out of ?nylon? bowstrings.

But there's also stuff about water wheels, how much more efficient overshot water wheels are than undershot water wheels, how many horsepower (1/10) you can get out of a man for 10 hours/day, how to build an aqueduct, how to build primitive pumps and the efficiencies of the various types. How to mill grain and build a water or wind mill, which you can hook to a pump or a stone to grind metal or a blade to mill wood. I think there's even a section about cooking, though that may be a different book I'm remembering.

I think there was nothing at all about medicine in the book. You'll definitely want the recipe for penicillin. There's a poster you can buy that has a title "Let's Say You've Gone Back In Time" that has a lot of things you'll want to know, but is mostly about 'inventing' stuff and taking the credit for it, which post-apocalyptical people won't fall for. Still, good info on that poster.

The book's not really what you're looking for, completely, but probably a good overview. If you've got a background in mechanical engineering and a couple of good craftsman you could probably build much of what the book discusses.