Hi Bikermama, congratulations on your new tablet and welcome to the forum. I'm going to move your thread over to the Acer Iconia Tab A500 Forum for you so folks can discuss your question with you and hopefully make some suggestions. Good luck!
Some people like to log out of Gmail so someone else can share the tablet without them reading all your mail.
If this is your aim, the tablet is probably not what you want, because Android does not make it very easy
to log out of an email program, or anything else that creates an account under "Accounts and Sync".
Luckily, you can delete and re-add Gmail accounts pretty easily from the Settings / Accounts and Sync.
But it is far from the best way to do things. The Tablet was designed to be a single user device.
If you want to give/sell the tablet to someone else go to Settings / privacy, and do a factory data reset.
EVERYTHING YOU ADDED TO THE TABLET WILL BE ERASED. <----- You've been warned.