For me, books roughly fit into six categories:
There are the reference books - Atlas, Dictionary, Thesaurus etc., which I keep near to hand for things like The Times Crossword.
Poetry books are scattered about the shelves throughout the house - these are to dip into when the mood takes me.
Then there are the books one feels one ought to read. This must vary from person to person - my list (taken from my bookshelves) is all of Dickens, Madame Bovary, Anna Karenina, Thoreau's Walden - I have read bits of them all from time to time but never from Page 1 to the end.
Travel books are important. I tend to borrow them from the library - people like Gavin Young, Paul Theroux etc. My two favourites, which I do own, are Wilfred Thesiger's "Arabian Sands" and Charles Glass's "Tribes with Flags".
Most exciting category - books I can't wait to read! These can be old favourites like "Brideshead Revisited" or books by any of my favourite authors - Sebastian Faulks, Ian McEwen, Evelyn Waugh, Iris Murdoch,Salley Vickers, Anita Brookner, Hilary Mantel, D H Lawrence - the list is endless.
But there is another category - maybe the most important for me -if I can't sleep and get up to make myself a cup of tea; if I am worried about something and can't really concentrate; if I get overtired and need to relax. Then I call on my "dip into" pile. I have read all of them a hundred times and am so familiar with them that I can easily find any particular passage I want to read. They take very little effort to read but always soothe and satisfy. Here is my list. I suspect most readers have their own list. What is yours?
Steinbeck's "Travels with Charley"
Waugh's "Brideshead Revisited."
Ronald Blythe's "Word from Wormingford", "Borderland", "Out of the Valley."
Roger Deakin's "Waterlog."
John Lister-Kaye's "Nature's Child."
Montgomerie's "Anne of Green Gables."
For my Desert Island it would have to be the Steinbeck!