Once youve sliced up what you need (choose seperate images,esc so you can delete them and change them if you wish to later)
Then go to File, save for web and save it as .index
Then find the html file you saved and right click, open with, dreamweaver or what you use to do it with
Then it will open the slices put together in the program and you can change slices if you wish(but they have to be the exac same size)
Hope Ive helped :)