Pulp fiction is probably good for a laugh. Dr. Drib has been posting some here for the Sony Reader -- he downloaded from
www.munseys.com and reformatted to his own specifications. Munseys offers all their books in MobiPocket format suitable for reading on your Cybook.
Also how about some classic detectives like
Sherlock Holmes,
Fu Manchu, or
Richard Hannay.
Fairy Tales and Folk Tales can be good, light reading. How about all the "color" books by Andrew Lang? Most of them are here at MobileRead, including
The Blue Fairy Book,
The Orange Fairy Book, and
The Olive Fairy Book. Lang also published
The Red Romance Book for the olders.
Lots of books intended for young adults also make fun and relaxed reading. There's
Tom Swift,
Doctor Dolittle,
Anne of Green Gables, and
Heidi.
Patricia has posted some books that might easily fall into the category of early "chick lit". Take a look at
The Professor by Charlotte Bronte,
The Princess Priscilla's Fortnight by Elizabeth von Arnim, or
Diary of a Provincial Lady.