What do you want to make with pyglet?
If you know some Python and have done gamedev before, the docs are sufficient: https://pyglet.readthedocs.io/en/pyglet-1.2-maintenance/
On the other hand if you don't know how to manage game entities and do collision checking and stuff like that, I'd recommend starting with cocos2d instead (which runs on top of pyglet): http://python.cocos2d.org/doc/programming_guide/index.html
Before you dive into either of them though, know that pyglet isn't optimized for ordered drawing which is needed in RPGs and other genres for tiles and characters to switch between overlapping or being overlapped. It's also not good for complex games since it's running everything purely in Python and has ridiculous overhead from wrapping OpenGL with ctypes.