Applying citizenship for my kid

Hi there,

I got the ILR last week along with my wife and kid. The kid was born in the UK last year
so he is now eligible for applying the citizenship. Now the questions are

1. Which form should I use to apply (MN1)?
2. What are the documents should I send with the application form?
When will I get my original documents back?
3. How long will the process take?

Thanks in advance.