Polybrush interface is very similar to 2D software UI. By default Palette and layers (objects) list placed at left, brush settings at right side.

For more comfortable work you need graphic tablet.

You select tool, color and start drawing at canvas. Difference is that canvas is located in 3D space and can move freely. 

This canvas called "Workplane" and looks as grid which follows cursor. Workplane is endless, user define only center and angles of rotation. Local coordinate system is shown at Workplane center.

Use this keys to control workplane:

[CTRL + Left mouse button] - rotate/tilt
[CTRL + Middle mouse button (or space)] - move by local x,y
[CTRL + Right mouse button] - move by local z

[ESC] - reset

You can also control workplane via interface at bottom of window. Use "Tilt" and "Rotate" sliders to select precise angles of rotation and 0,1,5 (10...) buttons to choose rounding for this angles.

All moves and rotations are recording to separate undo history, you can cancel last workplane actions. 

By the way, you can draw not only at workplane but also directly at objects. Change "Draw at" mode at left bottom corner for that.

Use this keys to control camera:

[ALT + Left mouse button] - rotate
[ALT + Middle mouse button (or space)] - pan (move by local x,y)
[ALT + Right mouse button] - zoom (move by local z)

[A] - fit object to view

You can use few windows with different views or just one window with images of that views at background.

Tools panel is placed at left side, main tool is 3D brush. Each tool is described in separate lesson.