An important part of ACT preparation is scheduling a date and time to take the test. Usually, the testing sites fill up pretty quickly, so make sure that you have made arrangements at least a month (further ahead in some places) in advance.
In order to find a location and time that you will be able to attend, you can get on www.ACT.org and click on your particular state. It will then give a list of possible locations at which you can take the test. Or, another option is to work through your local school system. They will have contact numbers that they can provide you with. Usually, public libraries also have the information for the area testing and would be able to help you with this important step in ACT preparation.