Might just be my industry (Accounting/Finance), but LinkedIn has also been great for me.

The first job out of college is always the hardest. I spent months sending out hundreds of resumes for a dozen interviews. But each job since then, I've only had to send out two or three before I had an offer.

Oddly, I'm back working for the same company I started at. I could be making more by job-hopping, but I realized that once I'm making enough money, I would rather take a pay cut then have the increased stress, poor benefits, and longer hours.