I live in MA, but received a 1099-MISC form from a company in CA, for which I did a little bit of work for. Do I report this to both MA and CA, or just CA where it was earned?

You have to report it to both states. First you complete your CA non-resident tax return to calculate the tax you owe CA on this income. Then you complete your MA return, on which you must report all income no matter where it comes from. So this income gets included in calculating your preliminary MA income tax, but then you get to take a credit for taxes paid to other jursidictions (namely CA). The result is that you are not taxed by MA on this income (unless your marginal tax rate for MA is greater than the tax rate for CA, which is unlikely).