Actually, it really depends what the airline is supposed to be doing in 2 to 3 years. If there are some plans to grow (I know, most of the growth plans are beyon reason), then a computerized system might be of value from the beginning. Learn to use it while you still have the time, not after having grown (Mistake most airlines do while growing).
Otherwise, pen and paper (don't forget the rubber), excel, acess, whatever you find on the PC/MAC/LINUX Box you are using may be of help.