The fastest and least error prone way to enter full songs is to divide the task in three steps.  First enter the melody notes (step 1), then starting from the top enter the chords (step 2) and finally starting from the top again enter the rhythmic value for the each chord and melody note (step 3).

By dividing the task in three independent steps you avoid having to change modes continuously, as would be the case if you would enter everything -- the chords, melody notes and rhythm -- sequentially. This not only saves time, but each step provides a basis for laying out the next step, thus avoiding mistakes.

The following three sections describe this process in detail.