the way i import pics is to go under the File menu-->Import; you can then pick from anything on your computer.
you can't use the import button that is at the bottom of the iPhoto window, it seems like that is only for digital cameras. everytime i click on it, iphoto tells me no camera is connected.
be warned, though. if you import pics, they are copied to your Home-->Pictures-->iPhoto library folder. so if you will have 2 copies of the pics, one set in the original location, and one in your iPhoto library. it doesn't work like iTunes (which allows you to import songs into your library by just linking to their original location)--it's kinda annoying.