https://danluu.com/startup-options/
https://github.com/jlevy/og-equity-compensation
https://gist.github.com/yossorion/4965df74fd6da6cdc280ec57e8...
https://news.ycombinator.com/item?id=2623777
Others in this thread have posted great advice. You want to know the most recent 409A valuation, and you want to see the cap table (you might be asked to sign an NDA, which is a reasonable ask). Also, its unlikely your role is going to give you enough pull for an acceleration clause or similar (in either the event your role materially changes or an acquisition occurs), so if you do want equity and they're willing to provide it, get as much as you can so you capture as much value as possible during your tenure and vesting period. The difference between 10 basis points can be material in the event of rapid growth and eventual liquidity. The answer is always no if you don’t ask.
The equity is more likely to end up worthless or a trivial amount more often than not, but you can take steps to derisk the devaluation of this component of your compensation.