Some Handy powershell cmdlets with syntax (note the pipe doesn't show up in blogger, so i'll use the word PIPE)

Setup Resource Mailboxes (like a new conf room).
1st, add create the new mailbox with EMC, then with EMS:

Add-MailboxPermission -AccessRights FullAccess -Identity ResourceMailbox -User Test1
Set-MailboxCalendarSettings -AutomateProcessing:AutoAccept

Add Mailbox Rights
Add-MailboxPermission "Mailbox" -User "Trusted User" -AccessRights FullAccess

Get Mailbox Sizes for all users
Get-MailboxStatistics PIPE fl totalitemsize, displayname

Set Rights for BesAdmin on a mailbox server (any time one is added)
Get-mailboxserver PIPE add-adpermission –user BESAdmin -accessrights GenericRead, GenericWrite -extendedrights Send-As, Receive-As, ms-Exch-Store-Admin

Get Mailbox Size/Location for 1 user
get-mailboxstatistics user.name PIPE fl

To get detailed information about the mailbox and what folders might be large, run this:
Get-mailboxfolderstatistics user.name

Force the GAL to update:
Get-globaladdresslist PIPE update-globaladdress list