Oooh! I actually got really good at drawing dragons from a book I got from the library from a few years ago (oml, it was five years ago )! I can't really explain it all that well, but this book is FANTASTIC! I mean it! I usually hate "how to draw" books (as, ngl, I have always been self-taught- I merely looked at how things were drawn, and I actually am a pretty good drawer, but dragons were so hard for me!), but this really helped! It is "Drawing Dragons" by Sandra Staple.
Best of luck, and happy drawing!! :)