Toffee and Pie by Pippa Goodhart
John and his horse each make a new friend when they travel to a new place. John and his family are always on the move: they live in a trailer that is drawn by their cob, Pie, and they never stay in one place for very long. When they arrive at the next new town, John isn't looking forward to starting another new school. But there he meets a boy called Tom - who loves horses as much as he does! John can draw fantastic horses and Tom thinks he's great, and suddenly it doesn't matter so much that John can't read or write very well. When the two friends meet up after school to ride their horses together - John on Pie and Tom on Toffee - John wishes he could stay here for ever. But soon it's time to move on again ... maybe they will be back next year.