Liferay 6 comes with new functionality , Page Templates. User can define a page with certain portlets/Layouts and Save the Page as templates. Later on while creating the new page , user can select the Page Template.
Here are the Steps :
1) Go to Control Panel -> Page Template
2)Click on add button to add new template. After adding the templates , page will show the link to open the template , click the link to open the Page template Page
3) Once the Page template is open , you can add as many portlets and apply layouts ,as you need them. Once you are satisfied close the browser. If you the browser URL It points to Template URL
4) Now you can go back to community, We will add the new Page in this community. When you will add the page you will see the option to select the Page Template.
5) Once the page is added, Browse to the page . the new page looks same as the tempalte. See the URL is the browser.
Knowledge Share 
Pingback: Liferay6 Preview – Site Templates « Saralgal
Can you help me with a related problem? I create a Page template and add a Portlet Web Content Display. Users create a page and select a custom journal articule. But if a template change the selected content lose. I searched about but I didn’t found nothing. How can i resolve?
Which liferay version are you using?
I’m having the same “problem” with Liferay CE 6.1.1.GA
I know about the checkbox “Apply Changes Done to the Page Template”, but then the changes on the page template would not affect the existing pages. This is not what I want.
The functionality I’m looking for is: updating the page template would not affect the web content display portlet defined on the page created with the page template when no content is selected on the page template’s web content display portlet.