Adding Page Links to the Main Menu

The main menu, or top navigation in the header of your store typically includes the selection of categories from your catalog. In addition, you can use URL rewrites to link to content pages and external websites, such as a blog.

Here We Go:

1.Create a Sub-category.

• Login to your admin panel.
• Go to Catalog -> Manage Categories -> Add sub-category 
• In my case,it is about-us.
• Assign a URL Key to the category.
• The URL keys of the category and linked page cannot be the same. If the page URL key is “about-us,” then make the category URL key “about-magento-demo-store”.

2.Creating a Re-Direct

• After completing step-I, Go to Catalog -> Url Rewrite management.
• In the filter box at the top of the Request Path column, type the URL key for the subcategory you created, and click the Search button. In this example, the Request Path is “about-us.html”

• Open That Record and after that Copy Target Path *  & make Redirect * to Permanent 301.
• Again Go to catalog -> Url rewrite management.In the upper-right corner, click on "Add Url Rewrite".

• Select Custom Option From Drop-down Menu.
• Fill the Url Rewrite Information. In Requested  Path Field, Paste the Targeted Path Value which you Copied before.
• Next, In the ID Path field, enter the URL key of the page to be linked. In this case, the URL key of the About Us page is “about-magento-demo-store”.
• In Targeted Path, Copy the same as you copied in ID Path Field.
• Save It & go to System -> Index management.
• Reindex the data & you are done with it.