It works both ways though. You can find out about employers, as well, to make sure the company is one you want to work for and the job is a good fit for your experience and skills.
LinkedIn company profiles are a good way to find more information on a company you're interested in. You'll be able see your connections at the company, new hires, promotions, jobs posted, related companies, and company statistics.
Glassdoor has a Companies & Reviews section where you can check out what employees have to say about the company they work for.
You'll find that most companies have a presence on Facebook and Twitter. Follow them to get the latest company news and updates. If it's a hospitality, travel or service oriented organization you may be able to glean some information from reviews on sites like Yelp and TripAdvisor.
Also, there are warning signs to watch for, if you're having reservations about whether this is the company for you. Taking the time to research companies makes good sense. It's as important for you to know that you want to work at a company as it is for the company to be sure that they want to offer you a job.
Image Copyright Getty Images Jetta Productions