In order to provide someone in your organization unlimited access to resources (i.e. your admins or an IT professional) without incurring charges, you'll need to create an unlimited plan.
Select Plans from the left-hand menu
Click Add plan to create a new plan
Give your plan a name and description
Click the blue Add Access/Discount button, and select Hourly bookings
Ensure the drop down menu under 'Resource' shows 'All Resources'
Under 'Access/Credit' click where you see 30 to open the drop-down menu. Select Unlimited
Leave the 'Price' field empty under the Billing preferences section
When you're satisfied, click Create
You're all set! Now you'll just need to assign the plan to the admin.
Need more info on the Schedule & Bookings?