Hello!
I guess nobody can help you if you don't tell us which LCD, which driver, etc...
I've written drivers for, maybe, 20 types of LCDs. The most difficult part is to get
the first pixel on the screen. When you can write something, even if it looks like
trashy data, you can be proud of yourself, 90% of the job is done.
Usually the maker provides sample code for initialization. From there, it's quite
easy to get a working driver.
As for data sheets, you can find many on the net.
Dora.