when should you use Wordpress?

I am working on a new project on php, with plethora of information. i am bit confused as of which method of development is better. Its a simple library website for a local community collage. Thing that confuses me more are

1) when should I be using Wordpress

2) how should I get started on developing to get it done quickly.

3) how should I start coding from scratch

A experienced guidance would be greatly appreciated.