There is a complete tutorial describing the technigues used to interface an LCD module to a microcontroller right here on the 8052.com site. Look at this link:

http://www.8052.com/tutlcd.phtml

This is assuming you are utilizing a typical character mode LCD with the defacto standard LCD controller. If you have another type of controller you can visit the manufacturer web site. Many sources such as Hantronix publish example code to interface an LCD module to a microcontroller.

Many of the examples you find will be in assembly language. It is a relatively easy process to translate such code to C. Keil has a host of simple code snippets in their knowledge base, including LCD interfacing. Check it out.

Michael Karas