Inscription
In order to really maximize your skill gain, you should take advantage of either a Skill Tutor Statuette or a Crystal Ball of Knowledge. It will help keep your training in the "Optimal" difficulty range.
0 - 40: Buy from Jillian The Inscription Instructor in New Haven [New Haven Buildings 1 - Magic 1].
40 -50: Complete the Inscription New Player Quest given by Jillian The Inscription Instructor in New Haven [New Haven Buildings 1 - Magic 1].
50 - 53.5: Make Poison scrolls.
53.5 - 67.8: Make Lightning scrolls.
67.8 - 82.1: Make Paralyze scrolls.
82.1 - 96.4: Make Invisibility scrolls.
96.4 - 100: Make Flamestrike scrolls.
0 - 40: Buy from Jillian The Inscription Instructor in New Haven [New Haven Buildings 1 - Magic 1].
40 -50: Complete the Inscription New Player Quest given by Jillian The Inscription Instructor in New Haven [New Haven Buildings 1 - Magic 1].
50 - 53.5: Make Poison scrolls.
53.5 - 67.8: Make Lightning scrolls.
67.8 - 82.1: Make Paralyze scrolls.
82.1 - 96.4: Make Invisibility scrolls.
96.4 - 100: Make Flamestrike scrolls.