More and more people are turning to the Internet as a source of learning. There are free online classes for a range of subjects, and some of the most popular ones are offered by Google. While the learning is free, you may be required to register with a massive open online course (MOOC) service such as Udacity.

Some of the courses even offer certification. Start by visiting Class Central.  Here are 10 you might want to check out.

1.Learning How to Learn: Powerful mental tools to help you master tough subjects. According the the course description, with this course you will be taught “learning techniques used by experts in art, music, literature, math, science, sports, and many other disciplines.” It’ll also cover “illusions of learning, memory techniques, dealing with procrastination, and best practices shown by research to be most effective in helping you master tough subjects.” It’s always a good idea to know how to learn.

2.Marketing in a Digital World. “A more nuts and bolts offering from University of Illinois at Urbana-Champaign. More than 150,000 learners have taken this course, making it one of Coursera’s most popular of all time,” Inc. reported. The course goes through how to use digital tools–from the Internet to smartphones to 3D printing–to market your product.

3. Get Your Startup Started.  Have you always dreamed of starting a business but didn’t know how to begin? This three-week course will give you the details, from writing a mission statement to finding funding.

4.How to Build a Startup. Okay, you’re company is up and running but now what? This is where this course might come in handy. According to the course description, “The main idea in this course is learning how to rapidly develop and test ideas by gathering massive amounts of customer and marketplace feedback. Many startups fail by not validating their ideas early on with real-life customers. In order to mitigate that, students will learn how to get out of the building and search for the real pain points and unmet needs of customers. Only with these can the entrepreneur find a proper solution and establish a suitable business model.”

5. Mindshift: Break Through Obstacles to Learning and Discover Your Hidden Potential. Often times we have learning obstacles, things that make learning harder or take longer. This top-rated course claims it can help you learn faster. From McMaster University via Coursera, it is focused more on career issues.

6. App Marketing. As of 2017, there were 2.8 million available apps at Google Play Store and 2.2 million apps available in the Apple’s App Store, according to Statista. So it is super important for your app to stand out from the crowd. This two-week course says it can show you how to market your app and get it noticed.

7. App Monetization. “This course is targeted to people who want to create apps or free online content, and have them generate income. That may make it a little less useful for some audiences, depending on your goals,” Inc. reported. This a month-long course.

8. Foundations of Business Strategy. This course will teach you how to think strategically when it comes to business. It’s an art. According to the course description, “In this course, we will explore the underlying theory and frameworks that provide the foundations of a successful business strategy and provide the tools you need to understand that strategy: SWOT, Competitor, Environmental, Five Forces, and Capabilities Analyses, as well as Strategy Maps. We’ll apply these tools in case studies of industry leaders Google, Redhook, Piaggio and Apple.”

9. Strengthen Your LinkedIn Network and Brand. Having a strong presence on LinkedIn can connect you with the right people and companies. “In any case, it takes approximately one week and has only one lesson, so it’s not a huge time investment. Oh, and it promises to teach how to write an email that gets responses. Now there’s a skill absolutely everyone needs, Inc. reported.

10. Work Smarter, Not Harder: Time Management for Personal & Professional Productivity. Who doesn’t want to learn how to work smarter? After finishing this course, the organizer, Coursera, claims you will be able to: Learn to plan effectively to achieve your personal and professional goals; manage resources both effectively and efficiently, and learn to manage expectations and say “No” when appropriate, among other “smart” things.