An excellent introduction to the physics of black holes this popular science book is much more qualitative than quantative. Suitable for undergraduate astronomy or physics students, or just those who like a really good pop. sci. book!
I got this book for an astronomy coursework project and it formed the outline for my paper. Informative but so easy to read.
It does help that the author was on the forefront of theoretical research predicting, along with Zel' dovich that a large star would orbit a black hole (as opposed to just 'falling in'). This later lead to a method for searching for black holes by searching for strong x-ray sources. The radiation is emitted due to friction as matter from the star is slowly sucked, spiralling like a massive plughole, into the black hole. (Cygnus X-1, the most likely candidate for a black hole, was discovered in this way.)
But back to the book.
It's very easy to read. You can sit and read it in one go or skip ahead and read about what it feels like to fall into a black hole or what it would look like to see someone fall in :)
Or even discover how we can use black holes as a power source.
The book also gives a bit of history of the theoretical ideas (and the people behind them!) that led to the ideas surrounding black holes.
There are even some very charming anecdotes from Novikov's days as a student which break up the more challenging concepts.
I think you do need a little background in science to really appreciate all the theory in the book but even without it's very well written (and suprisingly short!).
Excellent introduction to black holes