Always give a concise, meaningful title in the HEAD part of the document. Limit pages to a manageable size. Don't use 'Click here' for links. Make regular checks of the links in your documents. Minimise the size of graphics files and do not include large graphics files as inline images.
Large files take much longer to download, slowing the network and irritating the viewer.
Always provide an alternative to images, not everyone will be using graphical browsers. Provide a text alternative to hyperlinked graphics. It is important to remember that intellectual property rights, defamation and data protection legislation all apply to the WWW as well as other forms of media. On top of this, most institutions will have their own codes of practice laying out acceptable practice, which you should read before setting up any web pages.