Applying to OU / Student finance

Hello everyone,
I am planning to apply for Computing and IT in Open University this April. What kind of Documents/Paperwork do I have to have to apply in OU (Motivational letter etc. ). I sent them an Email but it's weekend so I though I might ask you guys.
Also, when do you have to apply for student finance? Is it after you know that you are in the uni or you can do it before that?
I am an EU student living in UK if that makes any difference.
Thank you in advance!

You just fill out the application then enrol i think, you apply for student finance before.

And if you fail to get into university and you get student finance?