There are a number good programming guides available on the internet which can assist you with HTML, CGI and other commonly used programming languages. 

A Beginner's Guide to HTML

NCSA's original beginner's guide to creating and coding HTML. 

Hypertext Markup Language

This is another good HTML reference guide.

PHP Manual

PHP is a scripting language that is embedded into HTML much like Mirosoft's ASP (Active Server Pages).   Unlike ASP, however, this language can execute on various types of servers, not only Microsoft NT servers.  This manual explains how to write dynamic web pages using this  server-side scripting language. 

PHP Builder

This provides further information for PHP developers.