I want to join my arm bones to the spine, and the figures to the hand/arm etc. But when I did this with ctrl+p it gave me several armitures when i only want one.
Select your armature
Go into Edit Mode
Select the bone that you want to make a child of another bone
In the Properties panel, go to the tab that has a picture of a bone or whatever, there you can find its parent settings. Set this to the appropriate bone.
e.g. Select finger bone, go to bone options in Properties panel, and choose lower arm bone as its parent.
Good luck. 