I don't have a lot of time right now, but some basics.
ALL switches are described functionally by the number of poles they have, and the number of throws they have.
Each switch has a "common" lug, which is always active, and then it has other contacts (called "Throws") which the switch makes contact with in one (or sometimes two) positions. In a basic single throw switch, you will have a common and one contact, and the connection will either be on or off depending on the position of the switch. In a double throw switch, you will have two contacts, a triple throw switch will have three, etc. Mini switches are usually double throw (abbreviated DT), though some are single throw (ST).
Essentially, a "pole" is a switch, but you can have multiple separate switches combined into one body. Each pole can switch between it's various throws. So, a double-pole/double-throw switch (almost always abbreviated DPDT) will have two double throw switches in the same body. You can get an awful lot of poles into a switch, with the largest number I've seen being about 20 on a rotary switch. Most mini switches are double pole, but you can find single pole (SP) and four pole (4P) mini switches pretty easily too.
There's a bit more, but I have to go now. I'll try to get back to this tonight.
So, a couple other things about switches (slider, rocker, blade, mini, or maxi; it doesn't matter, they all have certain things in common). There are two types of contacts for switches; make-before-break, and break-before-make. On a make-before-break switch, the switch turns on the next contact before it turns off the other. On a break-before-make, the opposite is true. Now, this leads to some interesting and useful stuff. For instance, the 5 position switch on a Stratocaster is a make-before-break DP3T switch, but it has five stops built into it. Two of those stops (the all important 2 and 4 positions) are just two of the throws at the same time, half way between the two positions, once they have "made" but before they have "broken." (Honestly, it could just as easily be done on a SP3T make-before-break switch, but no one makes one of those - at least, not that I know of).
So, mini-switches come in a whole bunch of styles, but the most common ones (particularly for guitars) are all DPDT switches. They come in a variety of types, though. An On-On switch (also sometimes called a On-(none)-On switch) has two positions, one for each throw. An On-On-On switch is a make-before-break switch with three positions, one for each throw, and one in between combines both throws. An On-Off-On switch is a break-before-make switch where the center position does not make contact with anything.
The back side of a mini-switch will have six contacts, in two rows of three. Each row is a pole, and the center contact of each row of three is the common contact for that pole. The other contacts are the throws, and they are opposite of the switch position (i.e., when you flip the switch down, the top throws are active).
So, a DPDT On-On-On switch would have the following positions -
● = closed contacts
○ = open contacts
Switch up:
○|○ /
●|● /
●|●/
Switch center:
●|●
●|● ------
●|●
Switch down:
●|●\
●|● \
○|○ \
I think that should explain everything you should need to know.
Light
"Cowards can never be moral."
M.K. Gandhi
