Bought these for a friend as a gift, will be asking for my own set of these for Christmas
They are by A. Wainwright but they have been updated as over time some routes have changed.
If you walk in the Lake District, these are a great companion.
Wainwright gives you some of the better, less busy/obvious, ways to approach your walks.
DON'T take just the books out on the fells though (always take/use an OS Map and Compass and know where you are).
Use the books to give you the routes which you can then walk from your map.
The nice thing about having the set is you will always have the book you need.
Best use these with latest OS maps - ideally (yellow) Explorer 1:25000, failing that (pink) Landranger 1:50000)