There are many moving storage or mini-storage companies to choose from when considering a rental unit. You can often find them advertised throughout your city or town or you can use the Internet to find them for you. Many sites offer free storage quotes through their moving websites. By simply inputting your zip code and the radius in miles you need available storage, you should have several in your area to choose from.
If you don't want to use a moving website to locate a local storage company, you can always do an Internet search for "self storage in ________" and fill in your city or town. There should be many results for storage units in your area to contact.