I will have some of the quick keys in here, which will help. I'm sorry for the lack of pictures, my capture program for some reason just doesn't want to capture this, so I'll simulate menus on how they will appear. I will also only cover the menus you have to know.
Edit
Undo CTRL-Z
Redo CTRL-ALT-Z
Undo History SHIFT-CTRL-Z
Cut CTRL-X
Copy CTRL-C
Copy Merged
Paste
As New Image CTRL-V
As New Layer CTRL-L
As New Selection CTRL-E
As New Transparent Selection SHIFT-CTRL-E
Into Selection CTRL-SHIFT-L
Clear DEL
Empty
Clipboards
Undo List
The edit menus commands are like your new bible, memorize them, and they will do you good, do not memorize them and be doomed to ever clicking in the windows. The one thing you need to know is the difference between the pastes. The traditional CTRL-V creates a new image, which is not what you want, always paste as CTRL-E. The Paste Into Selection command is how you place heads, which I'll get into much later.
View
Normal Viewing CTRL N
I'm only covering the Normal Viewing command because the other ones
you will have to select. Most of the time PSP autumatically makes
the image to fit the screen, and pressing the CTRL-N will get you into
normal viewing.
Colors
Adjust
Brightness SHIFT-B
Gamma Correction SHIFT-G
Highlight SHIFT-M
Hue SHIFT-H
Hue Map
RGB SHIFT-U
Load Palette
You should memorize all of these commands too. When you use layers,
and you don't like the color you changed the suit, here's where you'll
go. Brightness obviously changes the brightness of the image.
Gamma Correction, when using layers, is the only way to get pure black
skins. The highlight does nothing special. Hue changes the
color of your images, same with the RGB.
Lastly, when you are finished with making those great skins you have
to load a palette, better known as a pal, I'll get into this later.
Layers
New
Duplicate
Properties
Layers are like your rich friend that will help you in many ways. Not many people realize what layers are, but they are literally what they are called, something that's placed over another. You just need to know that heres where you get these commands when you need them.