Do I need brackets for my shelves?

Hi DIYers,

I am building shelves in a nook in my home office. The nook is 60 inches by 20 inches. I am going to build 2 shelves 60 by 18 and the top shelf will be 60 by 10 for a total of three shelves. I have already purchased and cut 1/2 inch plywood to size. My original plan was to just curt 2 inch strips of the plywood, and affix the strips of plywood to the walls of the nook and then lay the shelves on top, but now i'm second guessing myself. I plan on storing some books on the shelves so weight is a factor. I think I might need brackets. What is Reddit's opinion?

Picture of the nook

Submitted May 01, 2016 at 02:22AM by UnCorrelatedMe http://ift.tt/1TcchJU