Mass exodus on the cycle path on the Saturday and Sunday may be a bit too much for the kids but a good experience if they can ride with the flow. Shuttle buses from event to Spean and Fort William run all day (and has been free in the past)so you dont need to cycle.
Gondola and a walk down the course if the weather is good is highly recommended.
Camp sites can get a bit rowdy over the weekend and the Culicoides Impunctatus can get intolerable (Keep it covered rather than creamed)http://www.midgeforecast.co.uk/.Book early if you plan to camp.
Last year we booked a family room in one of the big hotels on the road out of town(heading south)for not much more than a camp site and had breakfast included (the Cruachan I think – be bold – ask for their best/coach rate).