Link a MacBookPro Retina to a Mac Mini

What do I have to do to let my MacBooPro Retina see the contents of my Mac Mini and vice versa? I use wireless to connect to my hub.

Turn on file share.

Mac Basics: File Sharing

File share is on on both computers and it still does not work.

Gotta give us more than it doesn't work.
Like what you've done, where you are, what is it that's not happening, version of OS X you're using on each machine...

"Assuming" you are talking about they do not show up in Finder...
Open Finder - Preferences - Sidebar tab - check everything under the Servers heading.

I have a MacMini using Mac OS X Version 10.6.8, software is updated yesterday, I got the message that it was up to date.
I also have a MacBookPro Retina 15" using OS X Version 10.8.4
I also have an Airport extreme which is wirelessly connected to both computers and a 1TB external storage.
I am trying to file share directly from one computer to the other.
File sharing is switched on on both computers.
I can see both computers on the left of the file window.
When I click on the computer I want to view it opens Dropbox
When I click on dropbox it tells me "The folder “Drop Box” can’t be opened because you don’t have permission to see its contents."

What do I do next?