Open it and choose Compression on the pull-down menu at the top of the video compression frame. Now can make adjustments to a number of features that will affect your clip's size and quality. Choose Cinepak as your compressor if you want higher quality compression. Choose Video as a compressor for a quick and dirty option. Ignore the other options.
Depth relates to the number of colors used.
256 will be adequate for many purposes. Quality refers to the coarseness of the picture. Medium is more that adequate for many applications. Movement begins to look jerky under 15 frames per second . But again the higher the frame rate, the greater the memory used.