The problem is there are several designflows in Expedition. And there is no document with an overview. Personally I've studied all the documentation in \docs\pdfdocs to understand possible designflows. The reason is that initially nearly all the tools in todays Expedition environment came from different vendors, and I even think none of them was initially from Mentor itself. So it was a great task to put all of that together and make it work. And documentation was left behind (as always).
As to Cell Editor I think "Library Manager Process Guide" (lm_proc_gd.pdf) has a good step-by-step description of that. I'll be glad to answer any specific questions