I need to use sub folders in Dw 8 image folder for example for navigation images I am going to add a navigation images sub folder under the main images folders is his okay?
Its a great idea to use folders to organize your files for your site, if that's what your asking. I would just keep it all lowercase though.
Hmm, I don't know dreamweaver well, so I looked it up and found this http://kb2.adobe.com/cps/140/tn_14028.html
you can create as many folders and at depth that you want ... you've just got to link to the contents in those folders appropriately. Using folders is the only way to go to keep your stuff orderly as your site grows ....