We got it through our regular insurance agent (we get our car and renters' insurance through him, as well). I think the amount depends on your life situation (kids, non-working spouse, mortgage, other debts, etc.) and your spending for the necessities. Also, I think *some* life insurance is a good idea for married folks, because who knows how you will react if your spouse dies? Will you need time off work to sort everything out with a funeral, will, probate, etc.? You might become depressed and not want to go to work, and not have enough paid time off to cover this bereavement period.
We each got $300K of coverage, and we have no debt, no mortgage, and no children. But I know I'd be devastated if my husband died, and that $300k would give me some breathing room from having to work, and would also be income replacement. I could definitely live on my income, but it would be much more difficult to retire early as we have planned--the $300k would make up for this. The same is true for him; I out-earn him right now, but he's in graduate school, and I can't imagine him handling work and grad school without me around to take care of everything else (cleaning, groceries/cooking, etc.). The insurance would give him a lot of options.