
A few comments above about number of graphics etc. Its not really the number of graphics thats the issue, its the size and quality of them. For photos use JPG format and try to keep the file size to below 30k if possible. That might not seem much, but when using a modem, 30k can take 10 seconds or so and you then need 100k+ of free RAM in the computer to decompress and display the image.
For diagrams, etc use GIF format and keep the palette down to as small as possible - if you use 4 colours on the picture, why bother using an 8 colour palette! GIFs will be a bit bigger physically, but are less compressed so need less head room for the browser to render them.
Don't use animated GIFs if you don't need to - they use a lot of capacity.