If you want current thinking on web standards, this is a site to look at: www.webstandards.org/

I recently did a site for our recorder society and ran it through the w3c validator until it passed. here it is, fwiw. all hand coded as I have found that most editors are either far too expensive for the amount I use them and/or add a lot of unnecessary code. (Speaking purely as an amateur, but I used to maintain quite an extensive site of materials for my students before I retired)

To Leeneia: You say don't use sans-serif font. This is contrary to the advice I received at a workshop on accessibility after the coming into force of the UK disability discrimination act. We were advised that Sans serif fonts are more easily read on screen by those with visual impairment. If you look at many recent recentsites the fonts are sans serif, including the web standards site I linked to in this message.