I did these tutorials on pentatonic scales. They cover all the theory and the practice very extensively.

http://www.guitartricks.com/tutorial.php?input=296
http://www.guitartricks.com/tutorial.php?input=722
http://www.guitartricks.com/tutorial.php?input=185

Originally Posted by: JoR0... how you decide which degrees to keep in and which to take out, since minor is sans 2 & 6 and major is without 4 & 7?

It seems like you've answered your own question there.

You keep out the 4 & 7 in major - and therefore leave in all the other scale degrees: 1, 2, 3, 5, 6.

You keep out the 2 & 6 in minor - and therefore leave in all the other scale degrees: 1, 3, 4, 5, 7.

Interestingly, the 4 in major is the 6 in it's relative; the 7 in major is the 2 in it's relative minor.

Hope this helps. Please ask more if and when necessary.