1. DON'T use any WYSIWYG editor (such as Dreamweaver).
Too long to explain why here.
2. DO use a standard editor for your code (Notepad, Notepad++ are very good).
3. DON'T get involved with any off-the-shelf scripts, such as osCommerce, Miva, Joomla, Drupal etc: it is a waste of time and you will get headaches just trying to adapt the code to your needs.
5. DO use www.w3schools.com
and mysql for samples, lessons and trials.
6. DON'T buy or read books on the subject: the web evolves faster than the books are printed!
7. BE TWO persons: a Designer and a Coder: they are different people! The designer makes nice static pages. The Coder (behind the screen and not often rewarded for his hard work) makes the site WORK interactively.
8. DO check/debug your site on IE6, IE7, Firefox at least: they make 91.5% of users.
9. Do check/debug on Opera, Netscape and Safari ONLY if it is a request from your client. (I can't give a *** for the 8.5% other users who are probably computer illiterate anyway...)
10. DO call back here: there are pros that can help!