to minimise the chances of refusal, you should have some savings in your bank (a few £k), but many people have got a visa while being on benefit or unemployed and having no savings, but they do risk a higher chance of refusal, as to how they can support their partner
passport and birth cert i don't think that is a problem
well if you've applied for the visa already, not much you can do, but wait
but if you have your own place and a job, with a bit of luck you should be ok
