schematics and cap question

[mieze245]

Hello all i will try to touch of something new. does anyone know of a book or has the knowledge. that states the purpose of schematic desinations. Ex. phono preamp.
"C1 is typically used to block d.c. from the cartridge, and is often a small electrolytic in the 1- to 10- uF range.
C2 is typically a large electrolytic, in the range of 10 to 100 or more, the large value necessary for extended bass response.
C3 and C4 are the RIAA equalization capacitances and are very critical to fidelity as well as basic frequency response.
C5 is a simple output blocking capacitor." (Marsh & Jung)

so where is the basic info that tells me this.

next is a cap question-not whats best ect. -application.

can i use a black gate "n" cap any where a polarized electrolytic cap is used?
are there any places NOT to use non polar caps. (power supply,
coupling, fliters ect.)