To check wireless AP information click Infrastructure.
At the top left click network -> wireless -> access points.
This will list each location, and from here you can either click the drop down option or just click on the name of the AP and it will show the list of IPs on the right.
If you click Events at the top left, you can see a list of events that have happened on the network. If youre wondering if an AP is down, it will show in the list (instead of going through the infrastructure tabs).
On the Events page, there will be a notification if an AP is showing high amounts of usage. It will say threshold of high utilization exceeded: current value (x).