Back and Next icons are not sufficient tools unless you explain where back and next lead. Users should also be able to easily navigate through information lists and data. This is especially important for long pages. Frames are excellent tools for providing convenient site navigation. Links can be placed in a frame where users will always have access to them.
Site maps are sometimes useful guides for large, complex layouts.
The computer screen puts limits on layout. Users see only the top part of a page when they first load it, so designers need to have important information and links at the top. Many users have 14-15 inch screens, and work at 640 x 480 resolution. They may lose content from the right hand side of a wide page. Many printers will also truncate the right edge if the content is crowded by graphics and frames.