The thinnest pixel of border you can use in tables is 1 at least with Adobe Dreamweaver 8. However, setting it to 1 pixel is not so simple because of shadow, which actually makes the pixel size look like 2. This short video tutorial shows how to set the size of border to 1 pixel, using CSS.
Learn how to Define the Local Root folder, sometimes called the Local Site folder. Defining a "Site" in Dreamweaver is the best way to start building your websites, so watch, learn, and have fun!