Did you know you can take a quick look at a document before you open it properly with apps like Pages, Numbers, Keynote and MS Office?
When you are browsing for a document to open, select it and press SPACEBAR to look at preview of it. You can even flick through all the pages. Then you can click Open if you’ve found what you were looking for!
Use the spacebar key to preview any document when your using Finder and even from Stacks (on your Dock)