We all know about Financial Capital. Often, we neglect our Human Capital. Here is a great article by Warren Ingram on self-investment. Educating yourself is very important. There are plenty of resources on the web which can help. Check out https://www.coursera.org/ and https://www.edx.org/ for some great online courses. And as always make sure you are reading lots of books!
Check out the article by following the link here: http://bit.ly/2aynplp