Quick reminder:
Make a new folder where your files in your computer are - give it a name
In DW choose Site → New Site and name the site.
Navigate to the folder you made above. Click OK
In the site folder make a new file and call it index.html
Details
Dreamweaver calls setting up a new site Define a Site. Remember that any site in DW is only on the computer that you are working on at present and that it will need its own folder. So if you are working on a web site in two places, each computer must have a root folder.
To start a new site:
First make a new folder where your files are on your computer - give it a name. This will be the root folder of your web site and will contain all the site's folders and files. The name should be something that will remind you of what it is.
In DW go to Site → New Site on the top menu bar.
In the box fill in the Site Name - it need not be the same as the folder name but would be less confusing to you if it was.
Fill in the Local Root Folder - you need to tell DW where the folder is, so do so by navigating to the folder you have made.
Click OK - you do not have to complete any more of the boxes.
You will see the folder appear in the files panel of DW on the right of the screen.
Next, make an index page: this will be the first page of your web site.
Mac: command+click on the root folder; Windows: right click on root folder this will bring up a menu - choose New File.
A file icon will appear in the files panel called untitled.html. Change the name to index.html. Always name it index.html and add nothing else to the name. This page will have a separate Title which will be the one found by browsers and search engines.
Note that the File Name and the Title are different things.
Open the new page - see the Title box at the top of the page - called untitled document. Change it to your title. It is important to give this a full name - it can have several words in plain English, with gaps and capitals where you want. This is what search engines will show, so plan it well. Do not leave it as index or call it home, although it is likely to be your home page.
See below for where to type in the page title.

Next you can make some folders and files: see the files and names page.
page updated 27/5/10