When you begin a site, organization of the site is perhaps the most important thing you do. If you have no clue to the structure of your site, you'll end up eventually with a huge folder and one big mess! If the site is one that is already established, and you're now using Dreamweaver. The program can help you organize.

Basic parts:

text, images, media (flash or other movies)

If your site has several sections: for example, pets, homes, kids, adults, each section has it's own images, text, and media.

Files should have short names with no spaces. The extension is either .html or .htm (html is now the most common.) The very first file of a site is named [index.html]. If your site has several folders, each 1st page within a folder can be called index.html.