How to prune this apple tree

It doesnt look too bad and is part way to being a nice espalier. Firstly you can cut back all of the new growth coming from your side branches back to about 4 buds now and back to 2 or 3 in the winter. These will form your fruiting spurs and is called believe it or not "summer pruning". You can prune the side branches to whatever length you want but 6 or 7 ft is a reasonable length to let them go each way giving you a 12-14ft spread.

The top can be treated in two ways. Firstly you can just prune it to the height that you want and hope that further side branches grow where you want them too or you can cut if off just above a bud where you do want side branches to grow. This will generally give you 3 new shoots which will be a branch each side and a new leader. You can do this now but as your tree has fruit on it it can wait till winter. You can use this method each year to produce as many layers of side branches as you want.

To support your tree properly I recommend binning the canes and fitting some good vine eyes and wires to give it some substantial support because when it really starts to fruit you risk the side branches snapping clean off. Also clean away the weeds and give it a good mulch and an occasional good water if its a new tree.

You should be proud of that, its grand.

Spot on piglet, you've got the job of Apple production foreman

ok, how about my other one then? How should I prune this? This is more of a traditional 'grow in all directions' type.

And this may be a silly question but, as (before I received it) someone chopped the main stalk off does that mean it won't grow any taller?

You can cut the main branches back to keep it in a nice open shape. Whilst the leader has been chopped it may not grow taller straight up but will try to "go large" depending upon its rootstock and thus its vigour. All of the small side branches can again be cut back to 3-4 buds now and to 2-3 in winter to give you fruiting spurs for next year. Depending upon its rootstock, you may need to prune it hard every year or only every few to keep its shape.