It depends. If you're not going to raise venture funds, then wait until significant revenues are in place. The amount of salary you pay yourself will depend on a various number of factors (i.e. your personal circumstances, life style preference, etc.). Whatever you decide, keep the long term in mind by putting as much money you can back into your business, particularly in its early days.
If you've raised venture funds, then $75K is the general salary for a seed round and around $120K post Series A.