Any fairly large bookstore will have a section on martial arts, Aikido included. If you have some time to kill, just visit one and flip through some books. I can recommend Saotome Sensei's books, "The Principles of Aikido" and "Aikido and the Harmony of Nature"; they have great pictures and explainations.
Unfortunately, pictures can be deceptive. I just came back from a seminar with Ikeda Sensei (thanks Musubi Dojo for making me feel welcome!
), and if I took pictures of what he was doing, I'd miss at least half of what he was really doing because his movements have become so small and subtile.