What are the impacts of changing to employer B without completing exit formalities of employer A

[rajvarma]

Hi,

I am working from august,2015 with an employer A. Now i am offered an employment with employer B. However i signed a 1 year agreement with employer A. But the agreement also mentions that a two months notice is to be given is an employee wants to quit working. So I have emailed my resignation to employer A. The employer A is not agreeing to accept my resignation and is saying they have a 1 year agreement signed by me.
Can the agreement do any harm to me. I want to quit the employer A even if they do not accept my resignation(due to some personal reasons) and i will be working with the employer B from January,2016.
Now my questions are:
1. This is my first job so i want to know what documents i need to collect while quitting an organization.
2. If my current employer A is not interested in providing me with the necessary documents like W2 forms etc, then how must i proceed in order to get them.
3. Is the 1 year agreement signed by me will have any legal impact.

I am thankful to all the valuable suggestions that will be provided by you all.

Thanks,
Raj