[Zope] Zope and restricted access for different users

Hi, I'm a new Zope user so bear with me.... What I would like to do is create a specific set of users who will be redirected to specific subfolders according to the login and password they provide, starting from a main portal. I've tried with the acl_user system, but I don't seem to be able to get it right. I'm getting confused with the differences in authorisation, permission, etc. I'm only concerned with people actually accessing (viewing) the specific parts of a site. Can somebody point me into a starting direction here? Flip