SEM / Paid Search Rules of Thumb

[semscotty]

i'm putting together a doc for rules of thumb (or general guidelines) for paid search based on my experiences, and i'm also interested in others' input. things such as ad copy, bidding, etc.

i'm not looking for guidelines from google or yahoo - more like rules of thumb from SEMs.

i've had trouble locating something along these lines on SEW - anybody have a resource they can point me towards, either on SEW or otherwise?

thanks!