[NOTE: When I first answered this, I was thinking NEX-3 rather than NEX-F3, so the information about available controls is likely not the same. I will leave the information for NEX-3 owners, but if you have the NEX-F3 (a much more expensive and capable version of the NEX camera series), my myopic observations may not apply.]

If the pictures are still in the camera: Press the Play button (the right arrow in a box on top of the camera) to bring up the previews of previous pictures, and rotate the rear control to get to the image you want to check. On the top rim of the dial control on back, press the DISP part of the ring repeatedly to advance through the various display options. One view will have very little printed info on the image, the next view will add in the information about the date, shutter speed, aperture and other EXIF data recorded when you took the picture. The last mode shows histograms of the color channels along with the EXIF data.

If you have already downloaded the pictures: For a Windows system, just right click on the desired image in the directory it was downloaded to and select Properties, then in the Properties window select the Details tab. This will show you the same information that is stored in each JPEG image. Hoping this helps...