No more admin access for users

Allowing users of my online store is becoming too complicated to deal with. I really would like to end this whole "login to the backend" system and only allow my users to manage products in the same fashion as Etsy.com or Ebay.com does.

My users do not need to worry about customization, menus, pages, plugin settings or the like. In fact, I do not WANT them to even see that stuff.

Can someone pleae help me with coming up with some alternative? Maybe a plugin or sidebar please help! Thanks!