Stage fright is more common than you think.

Close to three quarters of Americans suffer from glossophobia--that is, the fear of public speaking,  according to the National Institute of Mental Health. Even famous entrepreneurs like Virgin Group founder Richard Branson loathe making speeches.

Just because it's common doesn't mean it should plague you. For entrepreneurs, in particular, it's most critical to overcome this societal anxiety. Effective communication in a variety of settings can often mean the difference between your company thriving or just surviving. Indeed, if you can bring a poised presentation to the fore, that can help attract customers, investors and other important stakeholders.

Here are three free resources to aid your self-improvement efforts: 

1. Introduction to Public Speaking, University of Washington 

This free online course is taught over the span of 10 weeks by University of Washington Professor Matt McGarrity. The online version of his popular class attracts roughly 100,000 students a year on average. Each week, you'll get an hour and a half of video lectures. Assignments include online quizzes, activities and four speeches. Students are also encouraged to videotape speeches and submit them for peer review. McGarrity hopes students can walk away from the course knowing how to design and deliver arguments persuasively and speak confidently with the appropriate rate, movement, projection and vocal variety.

2. Steal the Show with Michael Port Podcasts

The New York Times bestselling author, Michael Port draws from his experiences as an actor and speaker at events like the Inc. 5000 conference to produce his Steal the Show podcasts. His series began in September and revolves around making the most of every presentation and interaction. Episodes are, on average, about 20 minutes long, covering topics like how to pace your speech, interact with the audience and avoid filler words during a presentation. The 26 podcasts (and more to come) are free for your listening pleasure on your commute to work or next business trip.

3. Toastmasters International

Toastmasters International is worth a mention in any conversation about public speaking. While the nonprofit organization charges a low membership fee, the site also provides plenty of free resources. The public speaking tips section and video library are open to all and offer valuable advice on giving sale pitches, speaking to diverse audiences and preparing speeches. And you can attend club meetings as a guest however many times you'd like before deciding whether becoming a member is worth the money. The meetings, which occur in 15,400 clubs across 135 countries, are a place for people to practice giving speeches and receive and provide feedback. The hands-on experience has helped many over the years hone their public speaking skills.