Preparing your site for templates
In order to make use of Dynamic Web Templates you must change the site settings in Expression Web 3. Templates make use of metadata (Hidden information about the files in your site), but this feature must specifically be turned on.
Choose Site > Site Settings.
In the general tab, check the box labeled Maintain the site using hidden metadata files.
Note: You must do this for each site you create if you are planning on using dynamic web templates.
Click Yes when prompted to Add Expression Web Information to the folder.
Creating the template and the editable region
With default.html open, choose File > Save As. From the Save as type drop-down menu, choose Dynamic Web Template.
Click Save.
This creates a new document named default.dwt which is now your template. As noted above, whenever you create a template you generally must define an editable region or region. When you begin to generate new pages off of this template, the areas defined as editable can be modified.
In your page, click anywhere within the welcome header. In the tag selector at the top of the screen, click the tag labeled <div#main_content>. This selects this entire section and Expression Web highlights the area in a shade of green to indicate this.
With this area selected, choose Format > Dynamic Web Template > Manage Editable Regions (You can also right-click the section, then select Manage Editable Regions.)
In the Editable Regions dialog box, in the Region name dialog box, Type maincontent for the editable region, then click Add.
Click Close
A new editable region now appears on the page. When an editable region is selected in a .dwt file, it has an orange border and includes a tab with the name of the region. (The tab for maincontent happens to be covered by the Silverlight content in this case, however, it is there!)
Click anywhere within the News section and again, from the tag selector, click the tag labeled <div#sidebar>. Right-click the sidebar tab and choose Manage Editable Regions
Type sidebar for the Region name, then click add and close. With these two editable regions defined, you can now attaché the template to additional pages.