Job Offer? Use the Moment.

Be grateful. You aren't the only ones who've been through a lot to make this happen, and these folks picked you. Say thank-you.
Ask to think about it. The little person in your head may be doing your happy dance, but you're in the sweet spot. Press pause.
Go home. Talk to the people who matter to you. Look at your budget. Calculate your expenses. Can you live in this town/city/region on what they've offered? If you don't know, find out how much that costs.
DO YOUR DUE DILIGENCE. Know what the field is paying. AAM, along with many of the regional museum and statewide nonprofit associations, do salary surveys. Find them and use them. And for goodness sake, if you're in a field like development or IT that moves across the non-profit world, know what organizations outside museums pay.
Some of us are epically bad at math. Because your offer also includes monies dedicated to state and federal programs and taxes, use sites like this to calculate your net take-home pay.
If you haven't already asked, read the Employee Handbook. Know what working in this particular place will mean to you. If you have an elderly relative you care for, if you're planning a family, if your partner works long hours, these questions are all part of the calculus. Does it offer paid leave or only FMLA? Things you wouldn't have mentioned during the interview like you have a toddler and day care is $100/day are now fair game as you decide what you need.
Time is also money. What if your new employer offers full benefits at 35 hours/week? Your offer is 40 hours/week, but you have two kids in kindergarten and first grade. Can you negotiate for fewer hours? Yes.
Ask for assistance with moving. What if you don't know a soul where you're moving and you literally can't afford movers? Ask. A $2,000 or $3,000 one-time expense is better than losing a great candidate.
Ask for time. Do you need time off before you start to clear your head and settle your family? Ask.
Know your own value relative to the field. Are you the second coming when it comes to exhibit design or conservation? Do others call you with questions? Is the reason you're job shopping because you know you're worth more? Well then, don't throw it away. Use it.Joan Baldwin Image: Molly Brown House Museum