Studying layout design would actually be a good start!

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I'm fond of the Non-Designer's Design Book, personally:

https://www.amazon.com/Non-Designers-Design-Book-Non-Designers-ebook/dp/B00PWDFWEE?keywords=layout+design&qid=1540163316&rnid=2941120011&s=Kindle+Store&sr=1-3&ref=sr_1_3

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Design School: Layout is good too:

https://www.amazon.com/Design-School-Layout-Richard-Poulin-ebook/dp/B079N6HLQ2?keywords=layout+design&qid=1540163316&rnid=2941120011&s=Kindle+Store&sr=1-1&ref=sr_1_1

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If you really want to get into it, a book on color theory wouldn't go amiss either. :)