Looking on how to create an image like the colored circle in the background of this image. How to I keep everything equal?
Not worried about the distressed effect (that's easy for me).
A. Make a circle and add a line, clone that line a few times (Ctrl+C - Ctrl+F )and drag one copy to the bottom.
Select all of the lines, and open the Align Panel (Window → Align or Shift+F6)
B. Click Vertical Distribute Space
This will space out all of your lines.
C. To get a larger gap between the segments, set the stroke thickness to desired spacing. Now delete the top and bottom lines, those are only needed for the spacing itself (and will cut off the top and bottom if left)
Select all the lines and go to Object → Expand (only choose Stroke)
D. Select everything (including the original circle) and open Pathfinder (Window → Pathfinder) and choose Minus Front
You can also follow the steps from my answer here.
Create vector lines the size you want, and duplicate them vertically, each spaced equally.
Make sure they are overlaying the circle, then go to Pathfinder--->Minus Front.
That's all there is. If you don't know how to duplicate the lines, select one line, right click 'Move', choose the distance vertically and horizontally you want to move the object, then click 'Copy'. Now if you want to repeat the action, just select the copied object and (in Mac) hit Command + D (D for duplicate). That will multiply the object in that direction as many times as you desire.