Aishaa,
You can set which shared borders to use in a web by default. For example, set the top border to be shared by default. Then, when you create a page for your web, the new page will automatically share this top border.
Note After you set shared borders across a web, you can change this setting for individual pages.
On the Format menu, click Shared Borders.
Click All pages.
Select the borders that you want to appear on every page in the current web. If you select Top or Left, you can also choose to include navigation bars.
So, after you've gone to Format, Shared Borders and set your default to apply to all pages. When ever you create a new page, it will have a shared border automatically by default.
I use it just on the bottom of my pages and it shows as soon as I hit the new page icon.
Hope this helps.
Jim