webpage design approach elements

hi,
ive got to do some research for school project- title is: designig a webpage(+an example)

im interested in a good aproach to this theme.
a somekind of a study.

perhaps, what are the key elements that the website competition is based on..
can you help with some links or examples, please.

some elements might be:
1. content (this is probably the most imporatant)
2. navigation (which is how the website is structured)
3. there should also be included HTML basics
4. one theme is about grafic (how is it working-optimatization etc,..)

any suggestions?
or link to some .pdf, or .doc files (ideally it would be around 20 pages research, it could be shorter and i could add content by myself, if just there is a good basis)