Don't restrict yourself to only considering prints, investigate other mounting / presentation products such as foamcore or acrylic mounted ready to hang images. Different methods appeal to different people and being able to offer a choice is a valuable marketing tool.
Don't sign images. If you are having them printed at a decent lab they will just about always have your name and or file name number printed on the rear. Make your self some stickers to go on the rear of any product with your name, contact details and image title. Avery type inkjet labels work well for that sort of thing. That way the purchaser will always have a record of where it came from and when their friends admire the work they will also know how to get in contact with you to purchase one or more for their house -------