Hey I have 2 questions how do you activate a camera I tried to activate 2 different cameras but it didn’t really work.
To answer your first question to active a camera first select it with rmb then do ctrl-Numberpad 0 to make it the active camera.
As for your 2nd question … 
I can answer the second question…lol
good job calvin; your minitut is now on my hard drive. thanks.
No how do you switch from one camera to another in an animation from different frames.
As Hazza said, make one active. then render your animation frames, like 20 thru 30, using that camera. Switch cameras, and animate frames 1-19 using the other. Render out to an image sequence. When you then Play frames 1-30, the camera switches at frame 20. For info on rendering out sequences, see http://mediawiki.blender.org/index.php/Manual/Rendering_Animations
It shows me how to render what window allows me to activate cameras.