DFS Mapping and rights

Guys,

About dfs, how should i offer the dfs to the users? Through a policy? Lets say, my namespace is\\server1\namespace1   should i map the policy with the unc path server1\namespace1 ?

Also, about the rights, its impossible to add usergroups to the dfs ? Should i add the usergroups to the folders thats reside in the dfs?

thanks in advance.