Wideband Amplifier and Coupling Capacitors
What the text is referring to is how to handle the fact that the capacitors aren't ideal.

In theory, the impedance of a capacitor goes down proportional to frequency indefinitely to infinite frequency (and therefore 0 impedance).  Real capacitors only exhibit this effect up to some maximum frequency.  Beyond that the impedance starts to go up again.  This is due to some inevitable series inductance, and can also be a function of the dielectric.

The lowest point on the impedance versus frequency curve of a capacitor is referred to as its resonant frequency.  That's where the inevitable inductance actually works with the capacitance to make the impedance extra low due to resonance.  Basically, the cap becomes a series L-C at the point.  Take a look at a ceramic capacitor datasheet and you will see this dip.  It's usually a little below the impedance you would get just by extrapolating 1/f to higher frequency.

Unfortunately for you, the impedance then starts going up quickly after the resonant point.  This is because the series inductance dominates.  The impedance of the inductance goes up proportional with frequency.  Basically this means that the capacitor is no longer a capacitor above the resonant frequency, and therefore not much use as a capacitor in a circuit.

The text is telling you to use several different caps with different resonant frequencies to cover a wider frequency range.  The high-value caps will have lower impedance at lower frequency, but also hit resonance and become useless sooner as the frequency goes up.  A lower-value cap in parallel can then pick up the slack at higher frequencies until it is no good either.  Then a even lower value cap may be able to provide a lower impedance at even higher frequencies, etc.

For this kind of application, you really need to look at datasheets carefully.  Different models of otherwise the "same" cap can have significantly different frequency responses a the high end.