Create several Ideabooks and name them based on the way you want to organize your photos. Then go to the original Ideabook. Photo by photo you will have to click on them and then click on save to ideabook and choose the new ideabook where you want it to go. Once you are finished, you can delete the original Ideabook.

Actually, there is a slightly easier way. After creating new ideabooks, go back to the original ideabook and click to select each photo you want to move. For example, you might select every kitchen you've saved. Then go back to the top and click the button that says "Move Photos to..." That way you can move batches of photos at once.