TFT LCD interface with a Microcontroller: Getting Started
The Renesas R61581 is an intelligent display controller that handles all of the high bandwidth tasks needed to refresh the display. The control interface allows a microcontroller to send commands and data to load the in-built video RAM.  It is an ideal choice to drive with a medium scale microcontroller.

The datasheet can be downloaded here.

Much of the datasheet refers to connecting the controller to the LCD glass, which you won't need to worry about. The controller has a multitude of host (microcontroller) interface options, but the simplest and easiest way to start is probably by configuring it for 8-bit parallel data access (so long as the display gives you access to the IM pins to set this up, otherwise use what's provided by the display interface). The datasheet includes a comprehensive command reference.

When you can initialise the controller and write a few pixels, then you're up and running and can develop your graphics code incrementally.

Have fun!