Yes, if you’re unsure of what to do or how to approach the goals your working towards, you can watch the fundamentals of modeling and rigging, those will clear your doubts and you’ll be on your way.
https://cgcookie.com/courses/fundamentals-of-3d-mesh-modeling-in-blender
https://cgcookie.com/courses/blender-mesh-modeling-bootcamp
https://cgcookie.com/courses/learn-how-to-rig-anything-in-blender-fundamentals-of-rigging
I think a good way to approach the thinking is, see how things are in real life, you can imitate it in 3D to follow the same principals. Like a car for example, the factory lines it has where things are separated and come together later. The doors have to be a separate part from the chassis or they wouldn’t open. So if your modeling and rigging a car, just look for reference and think how it makes sense to work like in real life.
