Consider This

Use url rewriting to encode the parameters of long urs to make them SE friendly.

Always use Anchor Text for your menu links plus title attributes and make sure your file names always use a dash if more than one keyword.

Use Alt attributes on graphics with a full stop so that screen readers can tab through, name bullets, spacers and other design graphics with alt="" as this lets the screen reader know the graphic is part of the design and should not be read who wants to hear bullet bullet bullet bullet over and over again?

Never link your homepage or folders with the file e.g. default.htm default.html index.htm index.html index.php etc etc etc... link to the domain or folder in question.