Hi Steve
As the name RAW implies, the photos have not been processed. There are some viewers which support RAW files but they will not display them to their best.
I believe Irfanview and Picassa can be used and are free downloads. They are considered very good viewers.
You should however have recieved some software with your camera which will convert the RAW files for you to whatever format you prefer. TIFF is quite a common format but does produce very large file sizes. Plus side is that it is uncompressed. JPEG is a compressed format and much more common, giving sensible file sizes and its unlikely you will notice any drop in quality from the compression.
If you dont have the software then you may be able to download it from the Nikon website. Another great conversion program you can use is Rawshooters Essentials. Download here.
http://www.download.com/RawShooter-Essenti...2.html?hhTest=1I have been using it for years and prefer it to the software that came with my camera. There is a superb tutorial with it explaining how to use it.
If you want to splash out cash. Adobe Lightroom is tops.
Hope this helps
Don
http://www.irfanview.com/main_download_engl.htmhttp://picasa.google.com/download/