First off the truss rod is used to adjust the neck relief not the string action.
There are two main things you need to be concerned with here and they should be treat separately and adjusted in order.
1 - The neck relief which is controlled by the truss rod adjustment.
Tightening the truss rod will pull the neck back and decrease the neck relief/bow.
2- The string action(height) which is controlled by the bridge saddles.
The neck relief should be adjusted first and then the string action second.
Here are couple of YouTube videos that may help. There are lots more out there.
Also, here is a discussion on the forum that may help you.
You may also want to check the nut height, although I have rarely needed to adjust it.
@howard has a method of checking this and hopefully he will join in and describe it for you.