[See what hiring managers want.]
Indeed's Job Trends: Wondering what kind of positions are growing in demand? You can search any term to see the growth in percentage of posts that include the term. The kind of words that are showing up in an increasing number of posts: Facebook, iPhone, virtualization, social media. It's an inexact science—take a closer look at the kind of job postings that include the word "Facebook" and you'll find that many are either at Facebook or from staffing companies encouraging job seekers to find them on Facebook. But "virtualization"-riddled job postings are for IT positions, through and through. Bonus trend charts: job postings per capita, job market competition, and industry employment trends.
Bureau of Labor Statistics: This site is a bit of a beast, but it's incredibly useful. To start, hover your mouse over the Employment tab on the left, and click on "Employment Projections" in the drop-down menu. The most straightforward data is in the tables that start at the middle of the page. You can see the list of the projected fastest-growing occupations (physical therapists, biomedical engineers, dental hygienists, etc.) and occupations with the biggest declines (farmers and ranchers, file clerks, telemarketers, etc.). Back on the homepage, you'll see a tab indicating resources for job seekers on the left. Click it. You'll find a library of information on topics such as educational requirements for occupations that interest you. Say you're a restaurant manager and you want to move to California. You can search "occupational employment and wages by area" and find that the greatest number (by far) of foodservice jobs in the state are in Los Angeles, but the highest hourly wages are in Napa.