how do i make an animation by combining actions that i made?

im using blender 2.6 and i made some cycle anymations in the dopesheet tap.
how do i combine those to make one long animation?
also, when im changing scene, how do i do that? do i just put everything out of screen then apply location? and bring next scene to the camera?

Read up on using the NLA Editor (NLA = Non-Linear Animation) for methods of combining different Actions into animated sequences.

For complete Scene switches it’s often more practical to render each scene’s frames separately, then edit the resulting footage together in the Video Sequence Editor (VSE), rather than accomplish the scene-switch “in-camera” as a continuously rendered sequence. This is often done even when just camera angles are being changed, let alone the entire scene.