So its probably really hot there now. One thing you could do if space allows it, is to plant the right type of trees in a formation like this https://goo.gl/nChH4r in the east-west direction. This way, only the mid-day sun will directly hit your house. This reduces load on your HVAC system from unnecessarily being used.

For the right type of trees (grows fast, doesn't shed too much and doesn't fall over in a strong breeze etc), ask advice from a landscaper in yelp/craigslist. The garden section at some Home Depots might help you out.

More tips can be learned from just googling and learning about Passive Cooling techniques.

Go for the energy audit. This is done by real professionals and is generally not expensive.