I read the instructions, but they ain't too helpful.  I also tried to find an appropriate video with no luck.  So, which leg do I hold up, while sticking my tongue out, and which side does my tongue stick out of my mouth in order to ADD new notes in the Piano Roll View.

Double click. With smart tool. You can select what type note drops when.you do this.

can also click and hold, then drag (while doing you get the pencil tool).
then keep holding/dragging to go up notes, extend notes.
after that, if you aim in middle of that note and double click, you can keyenter values for the note.
 
rightclick and hold-drag to lasso select notes.
click + Ctrl key, to select and move/edit multiple notes.
click + shift key, to make a coninuous selection of notes.
click note in the pianobar/or list,  on the left side of piano view -> selects all notes of that key.
move and hold shift to move while retaining the timepostion
 
good luck

This video is helpful.
 
http://youtu.be/ruAnAPR6-hQ

To add notes at the chosen resolution double left click or Alt + left click. (Change draw resolution in HUD drop down - Middle mouse button or press T)
 
To draw notes to required length freehand, left click and drag but remember that this will follow current snap settings which may stop you from reaching an expected length, depending on how your preferences are set.
 
HTH

If you lift both legs at once, your tongue will be closer to the keyboard/mouse.Less strain to add the notes(nuts).

this video is good for beginner to intermediate
http://www.youtube.com/watch?v=ruAnAPR6-hQ
 
 
never mind, Oleman posted the same one :-).