If they're well-funded (Series A or later) and you're getting negligible equity (hopefully not), then you should take the same salary as an established company like Facebook or Twitter would offer you. Probably a bit over $100k base for 3 years of experience.
Take that starting point and adjust it for the amount of equity they're offering and how much you think it's worth. Now your goal is to get them to pay you no less than you're worth. :)
I'm not the best programmer in the world (jr level I'd say), but I sure as hell love what I do and I'm improving every day.
Currently my biggest tools are Ruby, Rails, Javascript (jQuery mostly), and HTML/CSS. Half front-end/half back-end dev in my day job.
email me: aanon2247@gmail.com if you're interested in talking.
note: obviously throwaway accounts
x years experience doesn't mean much if it's the same year x times
Probably true for x < 3 and often true for x < 7.On the other hand, a person still using the same coding skills they had in 1981 probably writes damn tight efficient code...or is a God of COBOL .
Hope you don't mind the attribution "a wise man once said [...]"
maybe "a stupid thief once said [...]"