how do I create a resource (room) in Exchange so it can be viewed like a calendar using iCal/Calendar?

There is no way to directly view Availability (free/busy) information in either Apple iCal/Calendar (Snow Leopard, Lion, or Mountain Lion) or Microsoft Outlook 2011 (through SP2, at least) for an Exchange 2007/2010 room or equipment resource.

However, you can grant shared access for your account(s) to the Exchange resource calendar through Exchange management tools. Once that is done, you can add it the client for review of its schedule, as if it were another person's calendar for which you have sharing/delegation rights.

Apple iCal/Calendar: Preferences > Accounts > Select your Exchange account > Delegation tab. Click the "+" to add the resource calendar for which you have access.

Microsoft Outlook 2011: File > Open > Other User's Folder. Enter the resource calendar's information as the User and choose "Calendar" as the Type.

As long as your account has shared access to the resource calendar, you will be able to see it listed as another calendar in either application's sidebar. This sidebar entry will persist until you remove it.