There are two general indications of a secured web page:

1) Check the web page URL
Normally, when browsing the web, the URLs (web page addresses) begin with the letters "http".  However, over a secure connection the address displayed should begin with "https" - note the "s" at the end.

2) Check for the "Lock" icon
There is a de facto standard among web browsers to display a "lock" icon somewhere in the window of the browser (NOT in the web page display area!)  For example, Microsoft Internet Explorer displays the lock icon in the lower-right of the browser window. As another example, Mozilla's FireFox Web Browser displays the lock icon in the lower-left corner.

Other Indicators of a Secured Web Page
Many SSL Certificate vendors (Verisign, GeoTrust, SSL.com, etc.) also provide a "site seal" to the owners of these web sites.  Common characteristics of these site seals include:

*High Visibility - Online merchants want you to see these site seals.  They want you to know they have made every effort to make their site a safe shopping experience.  Therefore, the site seal is usually located where you, the customer, can easily see it.
*Difficult to Duplicate - The site seals are designed to be difficult for thieves and scammers to duplicate.  Many times the site seal will have a date and time stamp on it.
*Verification Functionality - The site seal should have some functionality whether by clicking on the seal or by hovering your mouse over the seal.  The functionality should display detailed information about the web site you are visiting.

Please visit this article for more info - http://info.ssl.com/article.aspx?id=10068