They put it in an open position, where the birds could see all around, but also close enough to any bushes or trees so that the birds could dive into cover if they needed to. It also needed to be away from anywhere where cats might be able to hide and jump out at them.
They set up their birdbath, and put some gravel and little pebbles in the bottom (so that the birds had something to grip on to in the water and the honeybees would be able to climb out if they got into any difficulty). They filled their birdbath with rainwater from one of their water butts, but you could also use tapwater. You only need to fill it with a couple of inches of water.
The birds love it in the summer months because it helps them to stay cool, but they also need to drink during the winter too, so make sure you always keep it clean and filled with water. In very cold weather, you might have to break the ice off the top of it!! Brrrrrr!