teaching a set of complete beginners is absolutely the worst! It is very demanding because Aikido requires your whole body to move and people start with poor coordination and understanding of what is really happening. If at all possible get as many other aikidoists to help you - most people learn more when they are training directly with someone that at least knows the basics.
If this is a problem, you can run through things like a kata, but unless they feel how the technique should actually work they will take a long time to learn.
Another thing - what is the purpose of running a 3 month course? If they are just going to dissapate after 3 months (e.g. just a quick self-defence course) it may be worth doing it more in a jujitsu style, just cos it takes so long to get good body movement and people just find it confusing if you try to teach too much.
Good luck, but I don't envy you - luckily the people that stayed at my course have had the patience and determination to get through the period of 'this is all too complicated and doesn't work' to start doing very effective technique (in fact I was just talking to one of them about the fact that you can do counters to any technique, when she applied sankyo and I had to add; 'any poor technique'). I've found the people that stick at it are generally the people of stronger character, which makes the club all the better.