While you can always link to another website from the content of any page in your site, you may want a button in your site's navigation menus that simply links to another webpage. Consider linking to your company blog, for example, from pages like Blogger or WordPress. To create a button that links to another website:
You can copy the URL from the Address bar of your web browser with the page open by highlighting the entire entry after the http:// portion of the URL, and then selecting Edit on the menu bar and choosing Copy. Once you have copied the URL, right-click in the URL field of the Content Editor window and select Paste from the menu that appears.