This is aimed at Premiere Pro, but may help
Work through all of the steps (ideas) listed at http://forums.adobe.com/thread/459220?tstart=0
If your problem isn't fixed after you follow all of the steps, report back with ALL OF THE DETAILS asked for in the FINALLY section at the troubleshooting link
Read Harm on drive setup http://forums.adobe.com/thread/662972?tstart=0
- click the embedded picture in Harm's message to enlarge to reading size
- you need AT LEAST 2 drives for video editing, 3 is better
- some HD formats work better with (require) RAID
Read Hunt on Partitions http://forums.adobe.com/thread/650708?tstart=0
A link with many ideas about computer setup http://forums.adobe.com/thread/436215?tstart=0
Welcome to the forum.
If I am not mistaken, the Nikon uses the MJPEG CODEC. This ARTICLE will give you some background. Can you confirm that your Nikon shoots with the MJPEG CODEC?
What Project Preset did you choose at New Project?
When you have edited your Clips, is there a red line above them. If so, hit Enter, and the red line should turn green. How does the footage play then?
If none of that helps, see this ARTICLE, and give us as much info as you can.
Also, how will you need to deliver your Project?
Thank you so so much Bill there was a red bar above, so I did as you said and rendered it, and it worked! I am presenting it by burning it onto a disc, are you able to do this on this program? And if so, what kind of disc do I use?
Great news. To give you a little background, when there is a red line above the footage, it means that the smoothest possible playback will not be available, without a Render. It can also indicate a mis-match between the source footage and the Project Preset, but that would be visible, when one Imports that footage into a Project. When one adds an Effect, or any sort of overlay, such as a Transition, PiP (Picture in Picture), or Title, the red line will appear. The Rendering basically creates "proxy" files, used just for playback.
As for the delivery, you can author and burn a BD (Blu-ray Disc), or can burn a DVD, though for the latter, your HD (High-def) footage will be down-rezzed to SD (Standard Def) of basically 720 x 480. PrE can do either. One can add Menus, for navigation, or just keep the Project as AutoPlay, with no Menus.
Good luck with the editing, and the school project,
I'm so enjoying getting to know everyone's "personalities" on this forum. John -- you are a man after my own heart LOL