Combining the Fair with an 'Its a Knockout' style event for the children is great way of raising interest among the children and encourages parents to come along as well. For school Summer Fairs, ask the PE department if they can organise the 'Its a Knockout' event for you. Consider games such as Welly Wanging, Penalty Shootout, Hockey Dribbling, Netball Shootout and Beanbag Surprise.
A Summer Fair can raise a signficant sum of money. It does require considerable organisation, so start planning well in advance.
Invite the children to organise themselves into teams (teams of 6 works well) and charge a £5 entry fee per team. Agree on a maximum number of teams that can take part - 10 teams of 6 rotating around 5 events will take around 1.5 hours, leaving time for a presentation to the winning team. Use the entry money to purchase a good prize for each member of the winning team.
Try and borrow a Gazebo for your Refreshments area and Wine Tent so that people can relax in the shade (or shelter from the rain!).
Have a good mixture of stalls (see Summer Stall Ideas) with plenty of games for the children and adults to show off their skills.