ADP has been around since 1949 [1] and handles even single-employee businesses. It's far more of a value when you scale to 10+ as I recall, but even their one person pricing is far cheaper than this IRS debacle here. Don't forget that if you're a California-based startup, you likely have to file with the state agencies, too -- and that system is so byzantine it'll make you relish the time spent with the IRS forms.

Better still would be to call up any random bookkeeper from the local area. Payroll is ridiculously easy for those who know how to do it and is well within the competency of even a bad bookkeeper.

Just remember to always sign all the checks, no matter how small, and look at the bank statements every month. It'll take maybe 20 minutes a week and saves so much hassle and money later.

[1] https://en.wikipedia.org/wiki/Automatic_Data_Processing