Thanks for this post as I didnt know the 'grids' feature existed on photoshop, might come in handy. Come to think of it there seems to be a lot more I dont know about it
When PS is open go to View>Show>Grid and you should be good to go. To toggle the grid on and off the keyboard shortcut is Command-Apostrophe (Mac) and Control-Apostrophe (PC). Very nice tutorial James.