if you're like me, you'll be a pack rat when it comes to your library. Everything you create, you'll think you are a genius and you'll use it again and again. Chances are, though, you may not use half of what you store away.
That's easy to take care of. Go to your library window, and click once to highlight the item you want to get rid of, and then hit your keyboard's delete key. Agree that you want to delete the item, and click yes.
You can also name each item in your library. Click on the item twice, and a window will come up that allows you to give the item a name. I find this particularly useful when I'm doing a publication with a lot of advertisements. If you name your library's entries, you can go into the library window, click a pull down window at the top, and choose just the item you want -- and that one will be the only item that shows. This way, you'll be sure to get the item you want, every time.