I strongly suggest getting the textbook "Compensation" by Milkovich and Newman. It is the study guide for one of the Compensation exams under the CEBS program and goes into detail on setting up comp plans....down to ranges/grades, midpoints, etc.
Different job titles along with different years of experience will put employees into different job grades. It is possible that two people doing totally different jobs with different amounts of experience will be in the same job grade. Milkovich and Newman define "job grade = pay grade" to be One of the classes, levels or groups into which jobs of the same or similar values are grouped for comp purposes. All jobs in a pay grade have the same pay range -- min, max and midpoint".
1st step is to group different jobs that are considered substantially equal for pay purposes into a grade. Grades enhance an organization's ability to move people among jobs within a grade with no change in pay. To slot jobs into a grade, the analyst needs to reconsider the original job evaluation results....He goes on to say that they are challenging to design....and that resolving dilemmas requires an understanding of specific jobs, career paths and work flow of the organization...and involveds trial and error along with considerable judgment.
I strongly suggest the Compensation Management Specialist certificate from CEBS if you want to move into compensation management.