Imaginary and Complex numbers have the reputation of being difficult. Maybe it's their name - calling them 'Bombelli numbers' might not sound so bad. This work takes a non-textbook approach to the subject, but if you find complex numbers scary then I wouldn't necessarily recommend it to you - there are quite a lot of equations. On the other hand the mathematics isn't particularly difficult. I would say that it is aimed at the keen high-school students, who will get a foretaste of more advanced mathematics. Those with a little more mathematical knowledge should enjoy it as a bit of light reading.
The book starts with the history of complex numbers, which were accepted as legitimate mathematics by Rafael Bombelli in the 16th century. We also find out about Euler's famous equation eiπ+1 = 0. Nahin goes on to look at practical uses complex numbers, for example in electrical engineering. This is followed by a selection of algebraic tricks and techniques where such numbers are useful, including a discussion of the Riemann Zeta function. The final chapter gives an introduction to complex function theory. If you would like to get a taste of these subjects, but don't want to study them in detail then I would say that this is the book for you.