When a .gif file is tiled across a page, the resulting pattern often creates an effect which is visually disruptive. Use only very pale graphics. These take up a lot of space, and take a long time to download. People viewing your pages will switch off and go elsewhere. Shrink your pictures in a graphics editing package.
Most people dislike scrolling through very long pages.
They will often not read beyond 2-3 screens of text. The solution is to create separate pages, and put links between them. Hit counters These make any web site look very amateurish. If your web site is a hobby, you don't need them. If it is commercial, you will not want to reveal this information.