The unit of the capacitance is Farad, abbreviated as F. But F is usually too big to use in electronics, so the micro F, µF and pico F, pF are often used. 1 µF=0.000001 F, and  1 pF = 0.000001 µF.

The capacitance of a capacitor is indicated as a value in µF or in pF. The number in pF is usually too long, so a 3-digits annotation is used. The first two digits represent a two-digit number, and the third digit is the number of zeros to be added after the two-digit number. The list of the capacitors used in the FET Mic DIY kit are:

 Symbol Value on the Schematics Numbers on the Capacitor C1 0.01µF 103 ( = 10 000pF = 0.01µF) C2 1000P 102 ( = 10 00pF) C3 220p 221 ( = 22 0pF) C4 22µ/16V 22 ||, 16+ C5 0.47µF 474 ( = 47 0000pF = 0.47 µF) C6 0.047µF 473 ( = 47 000pF = 0.047 µF) C7 6800p 682 ( = 68 00pF) C8 4.7µ/35V 475, 35 ( = 47 00000pF = 4.7 µF), 35V C10, C11 330p 331 ( = 33 0pF) C12 6.8µ/40V 685, 35+ ( = 68 00000pF = 6.8 µF), 35V C13, C14 2.2µ/50V 225, 50+ ( = 22 00000pF = 2.2 µF), 50V CF 150P 151 ( = 15 0pF)
You may see some capacitors show a voltage value, but some not. Either shown or not, this parameter is a very important one. This is the highest DC voltage under which the capacitor is allowed to work properly. If you put a capacitor with a low voltage rating in a place on PCB with a higher voltage, the capacitor will mostly be damaged.