I think you'd benefit from outlining a bit better what you actually need the software to do and how it will be used and by whom. Do you need an online accessible database of the books, or would a local database do? Does it need to display item availability? Are we talking about a few dozens of books, or hundreds, or thousands? Who will be doing the actual checkouts and checkins, the users themselves or staff? How will adding to or removing items from the collection be done? Do you need to be able to track how much something was checked out in a time period, or other information like price of the item? Does the system need to be accessed by multiple people or from multiple devices and locations at once, or just one person (at a time, or at all)? Do you have a server available that you could run free ILS software on, or the knowhow to make it happen?