Networking is a critical component of any job search.  Creating and/or leveraging personal relationships will help you discover what job opportunities are available and increase your chances of being considered.  If you don't have a strong personal network already don't worry, just create one.

The first step in creating your personal network is to identify the executive responsible for recruiting at the companies you would like to work for.  Many companies provide the name of recruiters and their contact information online. 

Through your networking activities try to set up both job interviews and informational interviews where you can meet with people to learn about what they do, even if their company is not hiring.  Jobs opportunities will present themselves if you focus on getting to know as many people as possible in the field you are interested in.

And finally, unless your job search is confidential, don't be embarrassed to let people know you are looking for a job.  The more people that know and the more diverse your networking strategy, the more likely you are to find out about the perfect job.