Lesley I'll second what Nose Nowt says. Get to complete runner but take your original Adidas if you still have them. They will be able to see what you need by checking the wear on your trainers and watching you walk around the shop. I dont know anywhere "oop Norf" that gives better advice.
Wooj get yourself along to Complete runner on road out to Ilkley I'm sure you will know it. They stock loads of trail/fell shoes and have 40 years experience of all types of running. They used to sort my old man out back in the 80's !!
As booktrunk says dont let the weather put you off it's so easy to just miss a run. When I was training for London and was having a not so enjoyable run I pictured myself running down the Mall waving to the crowds and thinking of all the people I would help with the money I raised.
Most of all enjoy yourself but dont overtrain or you will be joining the hoards of people on here asking what the hell their ITB band injury is all about