I would start out by reading 1st and 2nd Samuel in the Bible. 1st Samuel 16 or thereabouts.
In doing something like this you should take the time to read about David in the Bible. That will give you your best information.
A good Bible search and one that I've used quite often is Bible Gateway
The King James version is where I usually search.
If anyone else has any philosophical viewpoints to share, I'd also be interested.
Oh, one other thing. Since you are doing this probably via Word or some other program, please post this essay for our readers to enjoy and proof-read for you.