Online courses catch you up on what books can't. Luckily, there are lots of great marketing resources available for absolutely free on the Internet.
Google for Startups
Google for Startups is an initiative that helps startups around the world grow. Summing up the best of Google products and contacts as well as useful tips for creating great things.
Google Digital Garage
Flexible personalized tutorials that increase your digital literacy, strengthen your confidence, and help you succeed.
If you would like to focus on the basics elsewhere, I can recommend the Czech portal Seduo.cz. If English isn’t a problem, you’ll have many more options at Udemy.com or Coursera.org.
More tips:
Learn2code.cz
Czech-Slovak portal with online programming courses in languages from HTML to C #.
EdX.org
Wide range of online courses from world universities like Harvard, Berkeley or MIT.
Alison.com
Free online courses from world authorities and experts.
Canvas.net
Portal pushing lifelong learning in various fields.