What type of books do I look for?

I always buy secondhand, usually from the charity shops, preferring to spend no more than £1 if possible.Below are two books that were 50p each:

I like to look for books without a shiny protective cover but needs must if the inside is what you want. More about shiny covers later!

Look at the spine of the book, you can see several signatures. A signature is several pages bound together, many signatures make a book. It won't be as obvious as these pictures as I have begun to strip the signatures down ready to use. More of that later:

Open the book and find the centre of one of the signatures. You want to be able to see stitching, which both these book have:

If you can't find any, it is a glued spine. Some people prefer glued spines, I prefer stitched as they work better for what I want to do with them. 

Try to not find books with too thin a page as it makes for more work in the next stage. The Mice and Men pages are thinner than the You're It, but again, for me, I can work around that.