[PretzelJudge]

The amount of equity isn't as important as the vesting schedule. Don't vest anything to your cofounder right away. You should vest on a four year schedule with a one year cliff. There are good reasons this is the standard.

As far as the amount, make sure the other person thinks it's fair. If they don't find the split fair, then it'll just create issues later. Better to give away 49% of your company and have it succeed than to continue to own 90% and have it fail.