Cycling Britain is a guide from the Lonely Planet series. It gives some good ideas for rides and plenty of information to get you on your way. The maps are not that detailed so you would be well advised to use in conjunction with an OS Map or GPS device.
The guide covers the whole of the U.K. with both city and country rides and is divided into sections for easy reference. Its likely you will read just the chosen area of your trip but keep it after for further inspiration.
In addition to routes and sights to see the guide also has sections on Health & Safety, Your Bicycle, Getting there and away and facts about Britain. While there are other books available including those with more local detail this book is a good starting point for the novice to experienced touring cyclist.