My friends over at CreativeTechs have a great tip to help you evenly distribute guides across your page in Adobe InDesign. You could do it the hard way, using measurements and a steady hand, or the easy way as follows:

• Set your first and last guide where you want them, then drag more guides out until you have as many as you need. You don’t need to worry about where they are, as long as they’re between the first and last.
• Now drag the Selection tool (solid arrow) across all the guides so they’re selected (make sure you only have guides selected).
• Now click on either the vertical or horizontal Distribute icon in the Control panel at the top of the screen. Your guides will automatically be evenly distributed between the first and last guides you set.

If you need more help, I recommend you click the link above because CreativeTechs has a great animation of the process.