Create a user with rights to query LDAP directory?

Hi.

I need to create a user to query LDAP, this is a Linux application that need to query windows 2008 R2 ldap and capable to validate user+password.

I have the app running, but using a Administrator user, Linux app give us a advised and say:

"Need a windows users capable to query LDAP to validate user+password, with the minimal rights for security reason"

Some could help, what group I can use or how can I setup my user?

Thanks.