A great site for learning
http://www.streaminglearningcenter.com/
And the excellent book he wrote
http://www.streaminglearningcenter.com/video-compression-for-flash-apple-de...
To target accurately you MUST know as much about the playback equipment. There's no magic bullet solution unless you go to a poor quality lowest common denominator. An old Pentium 4 is going to be very different than an i7 Quad Core with a good GPU and then figuring a good bit per pixel relative to frame size and frame rate of the target is important as well.
