Here is a list of typical usage scenarios and what account types and modules you need to configure.
Address book entries:
Account types:
Users (Personal)
Unix accounts:
Account types:
Users (Personal + Unix)
Groups (Unix (posixGroup))
Suse users may need to use Group (Group of names + Unix (rfc2307bisPosixGroup)) because of Suse's special LDAP schema.
Samba accounts:
Account types:
Users (Personal + User + Samba 3)
Groups (Unix + Samba 3)
Hosts (Account + Unix + Samba 3)
Samba domains (Samba domain)
Asterisk:
Account types:
Users (Personal + Asterisk)
Asterisk extensions (Asterisk extension)
phpGroupWare:
Account types:
Users (Personal + Unix + phpGroupWare)
Groups (Unix + phpGroupWare)
Zarafa:
Account types:
Users (Personal + Unix + Zarafa)
Groups (Unix + Zarafa)
Hosts (Device + Zarafa + IP Address)