WLLH - positions?

[friends]

I have only started to read my first book on poker WLLH.
And there is some confusion for me with some things in this book.
As Lee explains there three type of positions:
early 1-4
middle 5-7
late 8-9.
But on pre-flop we have SB and BB, are they in the early or late positions on preflop?
And the second question:
Lee advice to count calls when making decisions in the middle and late positions.
Example:
SB
BB
call
call
fold
call
me.
So how many calls before me: 3 or 5?

Thank for your answers.