Will you be using John Innes No3? If so, I think it will contain everything they need for the first year. No point in giving them too much and encouraging them to getting over excited.
Hi Vic. I planted a cherry tree last weekend but before doing so I rang into my local bbc gardeners question time with a similar question - my tree has gone into the ground rather than a pot. They advised to put some manure in and some food, but not too much. This was to both help with the moisture of the soil, help prevent freezing and also growth as although trees look dormant right now, they actually have buds which need food even in winter. This will give them a head start in spring.
good luck with it!
Are they coming by post from a reputable dealer? If so, they will be well packed and can be left in their wrapping in a cool, but not frosty place, such as a shed for a couple of days. Give them a drink when you unpack them and plant them out when the weather is mild and the ground not frozen.
If you get a delay of more than a few days you can heel in bare root plants. Did this with my cordons and hawthorn, dig a hole big enough and bung them in. Don't firm them down, just cover the roots with soil. As they are dormant they can last like this until you get round to putting them in the ground properly or potting. Still got a few hawthorn like this because I got delayed towards the end of putting them in.
Good idea then you will get more responses.