Ask HN: What contracts/paperwork should cofounders set up before starting work?

We're in the process of starting a potentially profitable company.

Does HN have any advice on what sort of paperwork we should setup amongst us cofounders regarding ownership percentages, vesting shares, etc. None of us have any experience with the legal aspects of starting a company.

Should we seek legal counsel or is this something we could take care of ourselves? (Keep in mind that we're all broke college students).

Thanks for your help! -Advait