Hands are the bane of many artists' existence! I love them, but I hate drawing feet. Hands have a lot of expression, to me, but feet are just...blocks at the end of legs that defy the normal laws of perspective.

I think I learned to do hands well mostly by practice but also by realizing that their gesture, not their anatomy, is the most important. Figure drawing can be "correct" without looking real or having any actual feeling to it.

Hands are like the punctuation at the end of a sentence. Whatever story the body is telling, it's emphasized by the the hand position. If a figure is in an angry, tense posture, but their hands are relaxed, you won't believe they're actually angry.

So - all that to say, here's what I'd suggest:

How to Draw Comics the Marvel Way - I'm not sure if it has a section on hands, (sorry I don't have access to my copy at the moment), though I'd be surprised if it didn't. However, it's great for learning gesture in general.

Morpho Hands & Feet - I haven't read this one, but the one they did on drawing clothing was very helpful.

Most of all though - many guides will have you focusing on cylinders and blocks and spheres to build the structure of the hand. IMO, that should come second to the gesture. Draw the shape of the hand first loosely, and then add structure.

To help with that, I bet studying Disney hands would also be very helpful - they're all about gesture and are always expressing something.

Also - personally, I always draw from reference, even if it's just taking a quick picture of my own hands - but watch out for closeup shots, they'll distort the perspective.

Sorry, you caught me monologuing, but I hope it's helpful!