Collins Gem Night Sky
Ian Ridpath, thee book to use while at the eyepiece, small, easily held in one hand, contains all 88 constellations showing stars, galaxies, clusters an nebulae.

Collins Pocket Guide, Stars and Planets
Ian Ridpath and Wil Tiron, a great book detailing the 88 constellations by month and then alphabetically, the 2nd edition has a black background for the starmaps, the 3rd has a blue background to the starmaps. Just about small enough to be held at one hand at the eyepeice.

Peterson Field Guide : Stars & Planets
Jay.M.Pasachoff, charts by Will tirion, highly detailed for its size.

DK Stars and Planets
Ian Ridpath. well illustrated mini atlas, containing constellations per month and a good  general atlas. !