Le Furet du Nord is a huge bookstore located on La Grande Place in the heart of Lille. It's…read morestories and stories of books and books and more books. And some magazines and some of the other random games and notebooks and the like that bookstores tend to sell.
Le Furet is a great place to spend an hour or two just wandering through and checking out the selection. They have a few assorted English-language magazines and a whole section for books, as long as you know where to look. They also have a decent selection of bilingual books, which I think is a pretty cool concept. But why not test your language skills and indulge yourself in the shelves upon shelves and sections upon sections of books en francais?