On Exchange 5.0, here is what I have for shares and security.
Admins and Exchange Service Account(ESA) have Full Control on all shares.
Share
Add-ins d:\exchsrvr\Add-ins Admins and ESA
Address d:\exchsrvr\Address Admins and ESA
connect$ d:\exchsrvr\connect Admins, ESA, Everyone(Read)
Resources d:\exchsrvr\RES Admins and ESA
Samples d:\exchsrvr\sampapps\client Admins and ESA
tracking.log d:\exchsrvr\tracking.log Admins and ESA