Unless otherwise noted, the level is appropriate for middle-school students and above. Popular books and textbooks are being published at such frequency that any bibliography is quickly out of date. The references that are listed here serve as a general view of what is usually available.
Levy, David H. Skywatching (A Nature Company Guide). New York:Time-Life Books, 1995.
DeVorkin, David, ed. Beyond Earth : Mapping the Universe. Washington, DC: Smithsonian Air & Space Museum and National Geographic Society, 2002.
A lavishly illustrated history of cosmology from ancient
times to the present, particularly rich in information about instruments.
By a leading historian of modern astronomy.
Ferris, Timothy. The Whole Shebang: A State of the Universe(s). New York: Simon & Schuster, 1997.
Little on pulsars, but this is among the best-written of
the popular-level descriptions of the history and status of modern cosmology,
by a premier science journalist. (Note however that the field advances
so quickly that within a few years all books get partly out of date.)
Pasachoff, Jay. Astronomy: From the Earth to the Universe. Pacific Grove, CA: Brooks/Cole, 6th ed., 2002.
These are two of a number of readable and well-illustrated
textbooks designed for introductory college astronomy courses, and accessible
to an advanced high school student with a strong interest in science.
Pulsars are discussed in chap. 23 of Kaufmann/Freedman and chapter 30
Lyne, Andrew G., and Francis Graham-Smith. Pulsar Astronomy (Cambridge Astrophysics Series, Vol 16). Cambridge: Cambridge University Press, 2nd ed., 1998
To keep abreast of the latest discoveries in astronomy, consult recent issues of Sky and Telescope and Science News, both available in most libraries.