I use Pledge Multisurface, I don't spray it directly on the equipment/speakers I spray it on the rag then dust. I also use "the air in a can" for the nooks and crannies of some of the stuff. I actually use the spay to wipe down my seats as well. As far as vacuuming we have a Kirby and that thing is an excellent vacuum cleaner. IMHO well worth the price of admission.
My wife;)....sorry, couldn't resist!
While this was gonna be my answer as well, I have to admit she was adamant about me being in charge of the care and upkeep of the theater. As she does 90% of the housework already, I thought me having to clean/dust the theater was a fair trade for me having one.