http://money.usnews.com/money/blogs/outside-voices-careers/2012/05/21/how-to-juggle-multiple-job-offers

A job offer is usually welcome news—unless it comes while you’re waiting to hear about a different job you really want with a different employer.

While many job-seekers might see this as a good problem to have, it’s a tough spot to be in. And most job-seekers aren’t sure how to navigate it well. After all, can you put the first company off, and if so, for how long? What should you say to the first company in the meantime? And can you take the offer but rescind your acceptance later if the other job comes through?