scales

I don't have that book, but they're probably the major scales - you just need to know which one is the keynote.

For instance, from a G chord, the root will be on the 6th string under the 4th finger. I'm guessing his diagrams also show notes under the 1st finger (the 6th of the scale) and the 3rd finger (the 7th of the scale)

For the others:

C form: root on the 5th string, 4th finger
A form: root on the 5th string, 2nd finger
E form: root on the 6th string, 2nd finger
D form: root on the 4th string, 2nd finger

A curious, and in my view, bad trend in recent books is to give "forms" for scales that run the full position, then let the student find the tonic within the form.

Aside from the fact that this gives the very WRONG impression that a SCALE can start on any note (it can't it runs from tonic to tonic), it makes it harder for the student to learn some very important relationships between scales and chords because you can't see how the chord fits into the scale -- with the result that you fail to understand why two scales played more or less in the same position should use different chord forms, and a total failure to understand inversions and voicings.

Play your scales from tonic to tonic, and learn the note names and the intervals relative to the tonic and to the other notes.

The patterns taught in books like Fretboard Logic SE will emerge, but you'll have a much more grounded understanding of WHY those patterns emerge, and more importantly, you'll be able to play up and down the neck as well as within a static position a lot more easily.

The scale forms look like this:

(string) (fingerings)

C scale form

1st - 1, 4
2nd - 1, 4
3rd - 1, 3
4th - 1, 3
5th - 2, 4
6th - 1, 4

A scale form

1st - 2, 4
2nd - 2, 4
3rd - 1, 4
4th - 1, 4
5th - 2, 4
6th - 2, 4

G scale form

1st - 1, 4
2nd - 1, 3
3rd - 1, 3
4th - 1, 3
5th - 1, 4
6th - 1, 4

E scale form

1st - 2, 4
2nd - 1, 4
3rd - 1, 4
4th - 1, 3
5th - 2, 4
6th - 2, 4

D scale form

1st - 2, 4
2nd - 2, 4
3rd - 2, 4
4th - 1, 4
5th - 2, 5
6th - 2, 4

Those look like pentatonic scales (5 notes), which is why they seem different from the scales you once knew and loved.

those are the penatonic scales in e minor

is each form the same scale?

and what is the best way to practice these things? the book suggests playing them all the way through (both going up and going down).

yes, each one of those scales is the penatonic scale
just different formulas, that is the best way to practice
them, go up and down, start slow and when you can play them
clean(no ringing strings, and full clear notes) then speed up, also
use a metronome.

Pentatonics (or any scales you're going to use) need to be practiced until they're second nature.

First, play them up and down. Then make patterns, like these (only the three lowest strings shown):

-----------------1---1-3-1-3...
-----1---1-3-1-3---3---------
-1-4---4---------------------

---------------1-----1-3-
-----1-3---1-3---1-3-----
-1-4-----4---------------


Once you have each pattern down cold, then you need to work at connecting them. See how the A form ends on the fourth finger on each string? And the E form starts on the first finger? Those are the same notes! So you can connect from one pattern to another... visualizing the whole fretboard in each key.

Work at shifting between patterns on each strings until you know exactly where you are at any given point.

Then comes the really fun part... forget the patterns. Just make music.