You should always learn from the best. Even if you are planning to do comic books or cartoons. Understanding the human form will free you up to chose any style that you want.
I have listed in the order from someone who is starting out, toward more advanced with an additional one at the bottom specifically for sculptors.
Don’t feel you have to get them all at once. Start from the top of this list and work your way down over the course of a year or two, otherwise you will get overwhelmed.
I would look at the following by Andrew Loomis’ Figure Drawing For All It’s Worth as a starting point.
It is vintage style and very idealised body types, but it’s all good stuff and will give you a nice base to build on. It also deals with perspective in your figure drawings.
Next, Bridgman. Constructive Anatomy. A more advanced look at anatomy with some nice plates to copy, copy copy.
Glen Vilppu - An excellent all round multimedia resource that you could take whilst studying the books above, as and when you are able.
Robert Beverly Hale - For learning how to use anatomy like the old masters. This would suit more intermediate students, especially those looking to produce more realism in their work. This and the following books are ones that you will return to repeatedly throughout your artistic career.
Robert Beverly Hale - Anatomy Lessons From The Great Masters.
Robert Beverly Hale - Drawing Lessons From The Great Masters.
The book below is a good accompaniment to the one above (same author) and will give you a good grounding in how to use line and form and your developing knowledge of anatomy in a sensitive and tasteful way, rather than just drawing anatomical plates without any rhythm or gesture.
Elliot Goldfinger - Human Anatomy For Artists.
This is like the Oxford dictionary of Anatomy for Artists. You wouldn’t necessarily study it front to back until you are more advanced, but its one that you will go back to for anything anatomy related in your art.
A go to reference that is more of an encyclopedia, you should consider buying Elliot Goldfingers (this one is not urgent if you don’t have the funds. Start small and work towards this as you progress)
Anatomy is a tough cookie to crack, just keep chipping away and it will give itself up, eventually.
How to Study them.
Once you have read the text for each section and understood it, you then need to get cheap sketchbooks or scrap paper and copy as much of these books as you can over and over again, Don’t worry about pretty pictures, just keep drawing, over and over again until you can draw the figure, in any pose, without referring to anything
Finally if you are studying sculpture, but actually, even if you are not, this is a great way to learn anatomy for both classical and digital 3d sculpting, this is a great book to own.
Modelling The Figure In Clay by Bruno Lucchesi.
He takes you through setting up the armature, tools, techniques and most importantly, building up from the skeleton and deep muscle masses to the surface forms and finally the fat pads and skin.
This will really help ingrain anatomy into your mind.