Try a search as there have been some useful discussions on this subject. Keep in mind that most drawings use 3-5 pen weights.
You might also want a few pens reserved for extra height pen weights that come in handy as base lines for elevation graphics etc.
For a start think through and list the types of drawings you typically have.
-penset for each typ. scale with color version for archicad and a grayscale version of each for applying to the drawing in the layoutbook. This latter gives you a preview of how it will print.
-it's useful to keep walls using the same pens for all pen sets. This allows you to easily adjust their thickness. For example on RCPs you can make the wall pens thinner than usual so the lighting and other ceiling fixtures as well as annotations pop out.
Erika
Architect, Consultant
MacBook Pro Retina, 15-inch Yosemite 2.8 GHz Intel Core i7 16 GB 1600 MHz DDR3
Mac OSX 10.11.1
AC5-18
Onuma System
"Implementing Successful Building Information Modeling"