overheating and loosing coolant fast

What is your question?

A little over a month ago my car overheated. Because it is summertime in AZ I didn't think much about it. The coolant reservoir was low so I filled it back up. For the last two weeks I have been having problems with it overheating again. Every other day I have to add about a liter of coolant or else the car overheats again. How would I check to see if it is an issue with hoses, water pump or radiator?