Speaking as an ex-landlord (ex due to VAT) with good experience in managing my tenant group, I did it the following way:
* Open enrollment (Yeah, a bit risky, but saved a lot of work for me.)
* $1 enrollment fee This allowed me to track joiners in my transaction history.
* Friends of tenants were free to join. Once a month I checked the list and weeded out non-paying members not associated with a tenant. I had tenants and friends all in the same role. Why not? I kept the list of tenants themselves in my Hippotech server anyway.
Allowed abilities for tenants (all others disabled - I used the 'Everyone' role to prevent the need for me manually changing people to a specific role):
* Parcel Identity
** Change parcel name ...
** Set landing point ...
* Parcel Settings
** Set music ...
* Parcel Powers
** Always allow 'fly'
** Always allow ' Create Objects'
** Always allow 'Create landmark'
** Allow 'Set Home to here'
* Parcel Access
** Manage parcel Ban lists
** Eject and freeze Residents (I had to disable that once when a n00b tenant ejected other tenants from his parcel. Can't have that between neighbours.)
* Parcel Content
** Return non-group objects
** Landscaping using Linden plants
* Object Management
** Deed objects to group (needed for radios & security devices)
* Notices
** Receive Notices
* Proposals
** Vote on proposals
I also had a "Builder" role with additional 'Edit Terrain' rights. Tenants got that temporarily on request when they wanted to remodel their parcel.
Hope that helps
