Barerooted trees

Yes.

Bare root trees (and hedging) are graded in cms. 40/60, 60/80, 80/100 cms etc.  

1.  Start small, 60/80 is probably ideal - the roots are narrow and insert into a slit easily and the plants are amazingly vigorous and really take off in the spring.
2.  Your main enemies are rabbits, weeds, deer & (sometimes ) drought.
3.  Therefore spray off the weeds properly - start now and be ready to spray again towards the end of October which should finish off the likes of bindweed, dock, nettle and the other nasty perennials.
4.  For reasons of moisture conservation and weed prevention put down LOTS of mulch round each plant after planting.  Grass clippings, bark, anything organic, and keep it topped up.
5. Talk to a planter, or watch a planting video (hedge and woodland planting is the same in this respect) to see what slit planting is really about.  There is a first rate video on the site at the end of this post.  
6. Choose the species that suit your soil, if you don't know which they are, take a look at nearby  copses/woods to see what is growing there.
7. Plant some understory amongst the trees to provide summer cover - snowberry, shrub honeysuckle, laurel, hazel that kind of stuff.
8. Make sure you have some evergreens for winter cover (the honeysuckle and laurel are great, cotoneaster too and wild privet.  Also some conifers for the same reason.

We use Ashridge Trees who ship all over.  I think their advice and the quality of the plants is outstanding - and they guarantee everything (not that we have had cause to ask for replacements in 5 years).  They also sell hedging which you may want to plant round your wood.

Hope this helps

You are most welcome - watching a wood grow (we planted our first about 12 years ago) is one of the most rewarding things there is.

Enjoy

Apparently smaller trees establish quicker and often overtake larger ones, but as my first post suggestd I am new to this and someone with more knowlege may be along soon

Smaller trees establish far faster than larger ones and are almost (but not quite) free by comparison.  A two year old seedling tree loses practically no root at all when lifted.  A 5-8 year old standard can lose 75-80%.  Until that is replaced, it will barely grow.