There are loads of great podiatrists out there but also a lot who'll go through the motions and just end up selling you an expensive pair of orthotics that won't fit in your fell shoes anyway.... so be careful.
Also, according to a very good and experienced sports physio friend of mine, almost all running injuries relating to the lower limbs such as plantar faciitis, knee problems and shin splints can usually be traced to a weakness in the glutes and/or core muscles. He's based in Stockport and really knows his stuff. His name is Tim Deykin at
www.sport-med.co.uk . He's a great believer in the value of preventative all-overs (a bit like an MOT) for folk starting out with new activities or changing training and is vehement that most new runners can protect themselves from injuries like yours with a bit of strengthening work before starting to hit the running. I'd give him a bell.