Microsoft Office email disaster

I run a small retail and design business. We have a desktop, 3 lap tops, iphone and ipad. And more mailboxes than I need or maybe not enough. Its a mess and everyone that has tried to fix it made it worse. Now I have deleted things I shouldnt passwords are at risk and i am basically in a ball. They need to connect, i want one account but access to other employess email and keep mine private. please send help