I am working with a photographer who is good at editing his images, but there is a specific thing that I wanted done to one of the pictures that he isn't skilled at.

I have a friend who does alot of editing and she can do exactly what I had pictured, so I asked if he minds someone else working on that one.  He didn't mind at all and is excited to see the finished product.  He actually sent me two cds of most of the high res. images we shot.  On the CDs are jpeg files and NEF files of each.  The NEF files are 12-15MB while the jpegs are 1-2MB. 

I know jpeg files aren't the best to work on, but I have never heard of NEF files (I always hear about RAW files).  I would think they are better because of the size.  I can't bring them up on my computer... I'm guessing I don't have the right program or something.  So my question is what are NEF files and are they better for photoshopping?

Nikon RAW files. for me I convert them in NX software that come with the camera to Tiff files.

Nikon raw files...CS4 or Lightroom 2 will open them.

It's a good thing you have the NEFs, because at 1-2MB each it sounds like those jpeg are of very low quality.

Download a trial copy of Nikon's Capture NX2 (you have 60 days to use it).  Let me know if you need the link.  I highly suggest using NX2 over photoshop in your case.  NX2 will read and apply the camera settings to the RAW files (NEF's).  Photoshop will open the file but apply no settings so the files may appear dull and unsharpened.

Also if you're curious to see what you have, and don't want to spend money - Google's Picasa (the latest version) will open them up for you to see as well.

http://picasa.google.com/