Hi eddiek, The tree sounds full grown and hopefully it's not been neglected for many years.
I think what I would do at this time of the year is just watch it and see how it developes and maybe just cut out any dead wood.
The sap is rising fast at the moment, so it would'nt be a good idea to start pruning now otherwise it could weaken the tree and leave it prone to pests and diseases.
In Nov 07 to feb 08 Take a fresh look at it and cut out any crssing wood wher branches are likely to rub.
Any long whippy growth can be cut back to approx 1/2, to encourage flowering buds to develope lower down the stems which hopefully will later bear fruit, with practice you will instantly reconise the flowering buds which are fatter and tend to stand out at an angle from the branch.
Always prune to just above a bud slightly angled towads it, if you leave any long stubbs above the buds it will cause die-back which can become infected.
Remember the three D's remove dead, diseased and damaged wood.
I hope this is enough advice to get you started and you have some bountiful crops. Tbird+