Here are some ways to do this:
Depending on how large the area is, you can have a professional do it for you or you can purchase cans of texture and spray them onto the paneling. Be sure to prep your paneling first!
You should apply a good base such as Bullseye 1-2-3 Primer but first you have to wash with warm water and baking soda to remove any dust or wax. Your primer can be tinted to the finish color you are going to use. Cover the primer with one or two coats of latex texture depending on how thick you want the finish. Always use a good quality paint so that you get a more professional looking job.
Here's a great post on hiding the lines on paneling.