If you are the owner of a resource account, you can grant permissions to this account, including full read access, and permissions to send messages as this account.
You can only do this from the full Outlook client (not from webmail).
First locate the security groups that give permissions to your resource account in the address book - for a full list, search for "ZZ", and then find the relevant groups.
Note that full access gives full read access to the account and does not imply the ability to send as, and that if you wish to share folders or calendars that are part of the account you should do this from the account itself - this method is only to grant full access to the entire account, or send as permission, as appropriate.
Open up the security group(s) in the address book, click "Modify Members..." and you'll see a dialogue allowing you to add people to, or remove people from, the group that gives access.
Please note that changes to group membership may not take effect straightaway.
If you wish to change the owner of a resource account, please contact the WBS helpdesk.