Seven principles of library development should enable readers to build effective collections while wasting minimal amounts of time, money, and shelf space. (1) Plan to spend money. (2) Resolve that bigger is not necessarily better. (3) Choose the media and formats that will make up your library. (4) Build your reference collection first. (5) Choose commentaries (and other sources) wisely. (6) Take advantage of local library resources. (7) Collect (and read) across a broad range of subjects.