Internships have become commonplace, and sometimes required, for many college students. However, they aren't always easy to get.

An internship is a pre-professional work experience that provides students, recent graduates and those changing careers with an opportunity to gain experience in a particular field.

According to an article by Liz Wolgemuth, a writer for U.S. News & World Report, internships are often very competitive and usually unpaid. Available opportunities can often be found on company Web sites and more recently on social networking sites such as Facebook, MySpace and LinkedIn.

"Internships at flashy companies are great for your résumé and possibly your skill set," she notes. "But you can learn sales at a small firm. You can work on terrific projects at little-known companies. The world is full of successful people who got their start at small-town spots and no-name firms."

"The world is also full of successful companies that were once no-name firms depending on employees and interns who were willing to take a risk on them," adds Wolgemuth. "When Google hired its first employee in 1998, the company could hardly have depended on its illustrious name. Be brave and look beyond a label. Then go work hard and work smart."

TheStreet has many tips for those seeking internships:

• talk with teachers - many organizations turn to professors to locate potential interns
• use your school - most colleges have a career services center that can offer advice, counselors and job fairs
• network with friends
• go straight to the source - it's helpful to talk with a company's human resources department to learn about internship possibilities
• update your resume
• practice interviewing
• choose the right references - it's important to choose a diverse group, including previous employers, professors and coaches
• look beyond your comfort zone - location shouldn't prevent you from applying for opportunities, and some companies will pay for relocation expenses
• don't rely on just one source - apply to more than one internship and use all available sources
• remember it's never too late - you won't know if positions are still available unless you ask

Once you've obtained an internship, there are a few steps you can take to prepare, according to Monster Career Advice: accept an offer verbally and in writing, continue to study the organization you will be working for to prepare for your position, buy internship-appropriate clothing, make sure all transportation and living arrangements are in order and that you'll be able to get to work on time and show up a few minutes early on your first day.