I've done Telford a few times and will be back again this year.
First suggestion would be take your time and have a good look round before you dive in too far. If you have room for purchases then you'll do very well this year but some stands will be busy and you may not have the room to transport what you buy ( I know Zoukie Mura have the new HO229 available this year but I think the numbers are limited).
Second the club stands are usually very good with people from all over Europe attending and some very specific clubs will be there again I'm sure (WingNut wings had their own fan club last year).
Third have a look at the contest hall when you can as you will see some amazing build in there.
Fourth look for the smaller stands as some of these are new ideas and new products. I've had some interesting chats with people on these stands and they are happy to talk about their products in great detail. I don't think they always get much attention with some of the bigger stands about.
Fifth check out the big manufacturers stands, Airfix and Revell have big stands usually and there can be some great new kits on them.
Sixth take lots of cash as you will find you will spend it anyway and dont be affraid to have a look in boxes on some of the trade stands as you can find some great stuff hidden away.