Difference btwn file size images when printing?

Specifically, how much difference will I notice between a small jpeg fine and a raw image taken with a Nikon D40 (6MP)?

Added (1). Sizes I want to print:

8*10, 8.5*11, 8*12, 11*14.

The question is not clear though i think it will depend how much big you want the image to be while printing.

the main difference wil be in the quality of image…

You might notice a little bit of difference but how large will you print? If it's quite small then no, I doubt it will be seen.

It will depend on how you process the RAW file, to an extent, but the RAW file will give better resolution.

Unless you are hurting for space, you should use Large Fine JPG if you shoot JPG's. There's no other reason to use Small. It adds too much compression, and that can lose even more fine details in your image.

The larger you print, the larger those fine details should be, and the more obvious the compression artifacts will be. At 11x14, you will see those artifacts. Depending on the subject in the image, you may see them at 8x10. An example is a portrait-type shot, where stray hair will become fuzzy or just disappear.

It is easy to downsize an image if you need to, but close enough to impossible to make one larger. Capture the image at the best resolution you have if you intend to print it!