SALARY

In Silicon Valley or New York, base salary around $80,000 - $100,000. Look at Salary.com, figure out the median salary for your position in your market, then subtract 10% because it's a startup and you're getting equity.

EQUITY

As far as equity, anywhere from 0.3% to 1.5% would make sense, depending on:

1. the number of people that they are planning to hire
2. how much impact you will have
3. the amount of stock they have available in the option pool

Post series-A, a startup will probably have between 10% and 20% of the equity set aside for employees (you can ask how much they have in the option pool. If they won't tell you, something is wrong). For example, if they have 10% allocated for stock options, and they're planning to hire 10 developers and 3 key executives, the executives are going to take about 5% of that and the developers will have about 0.5% each (with junior developers getting less and senior developers getting more). If the series-A is supposed to be used to build a product and they are planning to only hire engineers (and do marketing later) and they have 20% in the option pool, and they expect to need 10 engineers, you might be able to get as much as 2%.

Remember that right after the series A, a LOT of risk is eliminated for you as a "founder". Before the series is raised, you're taking a huge risk and so you might get founder-levels of stock (5% - 50%) for joining. After the Series A, some smart investors have validated the concept, and there's enough money to guarantee you a salary for at least a year or two, so the amount of risk you're taking is much much less, and you will get far less equity.

Great answer by Joel Spolsky already...

Another thing to look at is the amount of work you're expected to put in. Discussing this can be tricky, as some founders are not honest with themselves about this, and as a consequence cannot be honest with you.

Some (a few) startups run at normal (~40 hours) work weeks most of the time. If so, then your salary could fairly be set near your normal market rate salary (whatever that is for your skills / experiences / situation) and without equity. It could even be ~10% less than your normal market rate, if the job offers other perks (upcoming hot technology, camaraderie, no bureaucracy, fast track to promotions) that make this worthwhile.

In some startups the early employees work hard; sometimes 80+ hour work weeks. In that case I would negotiate for market rate salary plus an equity stake in the upper end of the Venturehacks table for my position. If they want to hire you as programmer #2, then it seems reasonable that they consider you a high performer (though perhaps not a superstar), and hence an equity stake in the upper end is fair...

You could feel them out on a trade, less salary to you in trade for more equity. If you think the company has great potential, then that trade could get valuable for you. It is of course a very high risk proposition. In addition, your negotiation partner is bound by the size of the options pool, and he needs enough options left to fill other positions as well.

In addition to your salary and stock options, also consider vesting schedule and terms very carefully. There is a good chance the other side will want a 1 year cliff, i.e. if you're fired or leave before 12 months employment, then you get zero shares.

This article at VentureHacks has some numbers.