Rear camber/toe shims + setups

[Richy888]

I hope you don't mind if i pick your brains on this For cars with a rear beam I've been reading and it seems the easiest way to adjust the camber and toe is by using shims. Is this a good way? or is there something better? Is it best to try source some for the car as eibach doing some I recall or to have your own made? Do you need to have a special washer or bolt so that when using them it keeps it square. Also has anyone have any link to anywhere to break down setting up a car in terms of camber, toe, caster, tyre pressures. or can someone describe the effects of each in more simple terms? Thank you