What?
Books are made from paper and card.
Where?
Paperback books should be placed in the household recycling bin.
Hardback books can be recycled if the covers and binding are removed which should themselves be put in the general waste bin.
Large volumes can be taken to most local civic amenity sites.
Check the waste services locator on this site.
General Comment / Tip
Why not pass them onto somebody else or donate them to charity.