Resources: html tags and validation
This is a really helpful collection of tutorials on xhtml coding, start from the beginning or pick a skill you want to learn: http://w3schools.com/html/default.asp
Don’t style your html pages using html! It’s possible but it’s not good practice, so just disregard those sections. You’ll be learning how to make your websites look pretty in about a week.
Here’s the link to the w3 consortium’s html validator: http://validator.w3.org/. Some common errors that won’t validate:
all html tags are lower case: <H1> or <EM> will not validate, rather use <h1> or <em>
all html tags must close: <p></p> or <img />
tags have to sandwich: <b><i>text </i></b>; not <b><i> text </b></i>
image tags won’t validate without an alt attribute: <img alt=”wonderful description here” />