I was hoping to build my melody by adjusting each note I selected with lmb by a cursor key.  When ever I use rmb, Sonar gives me a dialogue box instead.  Is there an easy way of adjusting notes?  Or is that really the way most people input notation?

Using the Select tool, you can drag a note up or down or sideways in the Staff view.
To lengthen or shorten the note in Staff view, you must right-click to open the Note Properties and change the length there.
In PRV, you can also drag the notes up or down or sideways, and changing their lengths, you just grab the end and drag it either way, no need to open the note properties.