Creating a new library
To create a new library, either click the "New Library" button in the iPhoto Library Manager window, or select "New Library" from the File menu. You will then be prompted to choose a name and location for the new library. To open your newly created library, simply double click the library (or click the round button next to the library's name to make it the "current" library, then relaunch iPhoto). The new library will initially be empty, and you can proceed to either import new photos via iPhoto, or copy photos from one of your other libraries using iPhoto Library Manager.