My friend introduced me to cloth, and I found it useful to look and touch the basic categories (AOI, fitted, PF, pocket). She directed me to a few of the big websites which had FAQ on them, and that helped, too. (Not that I'm suggesting you simply hand out links - but bringing a printout with a combined FAQ listing w/ answers might be nice to take home since your participants may be on preggo brain, too - like moi). A listing of terminology and the abbreviations for easier forum read is always helpful (I'm still trying to figure out the difference btw soakers, doublers and liners).
Also, what helped convert me (i was doing sposies until monster #1 was almost 1) was the explanation of how "dry bucket" storage and washing were possible.