Alan MacRobert's "Star Hopping for the Backyard Astronomer" (out of print, but available). For small - medium apertures.
For bigger stuff, the "Night Sky Observer's Guide" by Kepple and Sanner (3 volumes, one strictly southern hemisphere). Maps, descriptions for several sizes of telescopes - pretty much the standard reference today.

The NGC2000 is great - Dreyer's coded descriptions are easy to read and information-packed. $15 at S&T last I looked.

Beyond that, you get into atlases and catalogs of DSOs, and figure your own star-hops.