The following websites and tools can help you discover your particular interests and skill sets. They can also help you understand the skills required for specific positions and the potential growth of certain careers.
These resources can help you develop a target list of potential employers by industry type, geography and other variables.
These resources can help you research a company in depth and prepare for an interview.
In addition to researching any particular company, you should also research the industry within which it operates. This will give you a sense of the competitive landscape and the company's overall position within the industry.
These articles can help you manage your Facebook and LinkedIn profiles and use them to your best advantage when looking for a job.
List of job search / career Tweeps that you may want to follow in Twitter.
TIP: Don't forget to search Twitter by keywords as well. Some examples include #interns, #jobsearch, #jobs, #jobangels.