a little knowledge

I know just enough about HTML to be dangerous. In a previous life I worked on a digital project that required (fairly simple) coding and I felt I had a good grasp on how it all worked. The suggested tutorials were fine, if not terribly inspiring, and provided a good refresher. What I found useful from w3school was the list at HTML4.01/XHTML 1.0 Reference of common tags. As long as the web page does not becoming too ornate I feel comfortable enough. What I am not sure about is the reasons/need for the different Declarations.

p.s. while all summer colds are evil, I feel it must be said that a summer cold in Arizona when it is over 110 degrees is just hell. Luckily, I can't contaminate any of you, my virtual classmates.