I think I can recommend Body By You. If that's not available, then You Are Your Own Gym would work just as well--the exercises are pretty much the same in either one. I just went and scanned the first chapters of the BBY book to see if it would be a good fit for you. I ain't gonna lie, he DOES talk about weight loss, because I think most people pick up this kind of stuff with a goal to lose weight. However, he tells people that the thing to do is to be exercising, that weight loss is not the only goal, and that it is best to throw away your scale and just focus on improving what your body can do and everything else follows. He talks about how you can't tone a specific part of your body, how women who are afraid exercises will make them bulk up are operating on false assumption, and that workout needs really aren't different between men and women (though women aren't going to gain the same amount of muscle doing the same amount as men due to not having as much testosterone).

Minimum of fat shaming, I think--he talks about one client in the motivation section who started out at 230 and got discouraged and quit when after two months she weighed 221, but he wasn't calling her horrible for being fat or saying she didn't do good enough--he was pointing out that she had lost 12 pounds of fat and gained 3 pounds of muscle and had made very good progress and that it was really a shame that she quit because she had already set herself up for further success even though she felt she hadn't lost enough weight fast enough (and really, I think we know it's good that the book isn't telling people that they'll lose 30 pounds in two months, that's unhealthy and unrealistic). On the other hand, it did say that she continued her slow descent into morbid obesity, which is maybe not the best phrasing/attitude. You don't have to read these beginning chapters really, so you can skip over all that and just get to what you really want.

Because on the plus side, this book has what you want in spades, I think! It has five different movement categories and has a ladder of increasingly difficult exercise variants to do for each. You do an initial evaluation to see where on the scale you should start and then you just keep doing it and work your way on up to more and more difficult exercises. Another couple big pluses: it doesn't expect a huge time commitment or for you to have a lot of expensive equipment.

I'll also second thalia's yoga suggestion. Yoga isn't as nicely laddered as the bodyweight exercise book above, but you can definitely tell you are advancing the more you do it and when I'm not doing it I can tell because my lower back starts hurting. I subscribe to this YogaDownload site (if I wait until sale times I can get a year unlimited membership for $60 which is a cheap cost month to month) because I've found that it can be hard for me to want to go out of the house and pay class to class. Yoga equipment needs are fairly minimal--you'll probably want a mat, a sturdy blanket that you can make into a roll when needed, a couple yoga blocks, and a strap. Things I like about yoga:

* I feel like it has improved my balance overall, even during long stretches when I haven't done it--I'm much more coordinated now than before I ever started, because so many of the exercises made me pay a LOT of attention to my body and its balance
* There are a lot of things to try and pay attention to and do correctly
* It helps stretch out and balance out my muscles so that they ache less and aren't as tense
* Did I mention it is great for my back pain because it is so great

The downsides:

* Sometimes it gets a bit too woo for my taste
* I'd worry a little bit about not starting out in a class with real supervision to get a good foundation for all the poses; there's a lot of detail to get right
* I think it's a bit more demanding timewise, I feel like it's better to do a class for an entire hour over one that lasts 30 minutes, but sometimes that feels like forever!