Ferri's book is good and I'd recommend it too. But it depends on what level of complexity you're after, there are simpler books and more complex books - Ferri is somewhere in the middle, which may be exactly what you're looking for.
No one agrees with other people's opinions; they merely agree with their own opinions -- expressed by somebody else. Sydney Tremayne
Retired Jun 2011 at age 57
Target AA: 60% equity funds / 35% bond funds / 5% cash
Target WR: Approx 2.5% Approx 20% SI (secure income, SS only)