You should only need to bring yourself and any passengers.
There will be people in each group that have recovery gear, although this shouldn't be needed.
A CB is not really necessary, but if you have a CB radio bring it along as it is desirable for the leader to talk to the last car in the convoy. CB's can also provide a good laugh with chit-chat throughout the day
Warm, waterproof clothing (just in case)
Wellys incase you need to get out of your truck on a muddy lane.
Flask of tea/coffee + snacks + packed lunch if you are not eating in the pub
Camera and/or video camera
Wet Wipes/loo roll (just in case too

)
A basic toolkit is also a good idea, but again I would expect that between us we'd have enough should anyone breakdown.
My only other tips would be, check your car over the day beforehand (oil, water, tyres etc.) and check your journey time to our meeting point. Remember that if coming from the south via the M25 that there are roadworks between J20-23 (M1 to A1). Please allow extra time for this.
Finally, have a read of this document -
http://www.fronteraowners.co.uk/downloa ... ctions.pdf - It's an excellent guide to laning prepared by our own Trugga