If you follow the articles below you should be able to accomplish what you want.
1. An Introduction to Joomla 2.5 Menus
2. How to create a new Menu and Menu Module in Joomla 2.5
3. How to link to an Article in a Joomla 2.5 Menu
4. How to link to a Category in a Joomla 2.5 Menu
Like this Question? Tweet
Joomla Community Google+ Hangout #3
June 3rd, 2014
Thank you @RustyJoomla for letting me speak on the Joomla Community Google+ Hangout!