Take a look at Ki in Aikido: A Sampler of Ki Exercises
by Carol M. Shifflett ISBN 0-96534-253-0 available at Round-Earth Publishing
Look at the AikiNews footage of aikido practice in occupied Japan, where "martial arts" weren't allowed, so people practiced gymnastic exercises that involved no throwing, but was still aikido.
Children and the Martial Arts
by Gaku Homma ISBN 1-55643-139-2 also shows basic exercises that can be done by novices. There are also several nice interactive games that you can use to demonstrate various principles.