I thought I would create a page to link through to all the really useful resources I have found online.
** NEW ** - List of Races to enter - A race calendar that you can search by area or from a map view :)
Runners World Smart Coach - this will create a training plan for you based on a recent race time, your current weekly mileage and how hard you want to train.
An interesting article on heart rate training
Finding your max heart rate
Really good weather site
McMillan training times calculator
Hal Higdon's Marathon Training Site
Garmin Forums (for any queries related to GPS watches etc !)