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.