While the rest of the market catches up with Nest, here are some great videos guide to help you choose a programmable thermostat that's right for your lifestyle and schedule. There are also helpful tips on how to set the thermostat during the day and night. The second video is from SRP and shows how to install a programmable thermostat. An SRP energy auditor will also be able to tell you if your thermostat settings are best suited for your home. APS also gives some helpful advice here.
Your thermostat should be turned up while away, or during APS and SRP's peak hours, which are double the normal rates during the summer. Pre-cooling your home is a smart way to manage your on-peak hours by setting your thermostat several degrees below what you normally keep it at, just before peak hours start. Here is a general guide to what your thermostat should be set at while away. Then during peak hours, turn up the thermostat to avoid having the AC kick on. If your windows are shaded and your insulation has been properly inspected and installed, your home should hold a nice cool temperature for the duration of the peak hours. If it rapidly heats up, then it's probably a good idea to have an energy auditor check out why that's happening.
You can also view an article on what temperature you should raise your thermostat up to at this link. Find more information about APS time-of-use plan and SRP-time-of-use plan here.