Official Documentation:

Install:

Inkscape Egg Bot Extension: Driver First plot (or read our short version below: First Plot Getting started video: Getting Started

When mounting object - when you setup the pen it can contact it on all sides as it rotates. The cups are spring loaded. If you draw a line from the pen motor to the egg it should hit it at the widest part of the egg. If not slide things around.
Set the plunger - This should be tight enough that the tiny o-ring between two pieces of wood is at a position of 1/2 to 3/4 of the way compressed (per the site!)
Set pen height so when in up position tip is 1mm - 3mm off egg.
Make sure everything is aligned.
Install pen
Goto Inkscape -> Extensions -> Eggbot Control -> Setup
Set pen so when up it's about 5mm off your object and when down it is touching with a little force.
Hitting apply will toggle the up/down motion.
Down motion should be set roughly horizontal
Default is to start with pen centered on top of Egg (see checkbox on Options tab)
Move pen to default position (use manual screen, pressing apply to move it). Negative values are valid.
When egg is mounted and spun it should not wobble!

Draw something then in the plot tab of the Inkscape plugin (after Calibration) press apply. The Egg bot will begin to print.

Egg bot also comes with many plugins you can use to generate patterns.

Basically anything that is room temp, clean and dry.