How do I define the courts for automated fixture bookings

You need to define a court set. Here's a simple example assuming you have two 40 minute courts with slots from, say 7:00pm 10:20pm.

Go to Manage club, select the Courts Tab and the Court sets sub-tab. Double check you don't already have an appropriate court set - maybe one called Team matches or something. Assuming not:

1. Click the green New button, enter an appropriate name (e.g. "Team matches") and confirm.
2. Select Expanded format mode
3. Assuming you wish to cater for matches potentially falling on any week-day, do the following 5 times with each of the week-days (Mon - Fri) selected in turn: In the grid, click on the buttons for courts 1 & 2 for each of 5 successive slots from 19:00

Congratulations - you've created a court set!

Now we need to "apply" that court set to the county league event: Go to the Conditions tab of Hosted events, choose the county leagues and, under Court access tab, add the court set under the panel Court sets for auto/speed booking and click Confirm.