Both actually. Speaking for myself... I start with video. It is easier to find, easier to follow and easier to implement. Now when you finish with video course

Both actually. Speaking for myself... I start with video. It is easier to find, easier to follow and easier to implement. Now when you finish with video course, search for "best" or "amazing" book for that particular language or framework. Because of video course introduction, most part of the book will be like "seen somewhere" or "read somewhere". so the reading of book becomes tolerable and more understanding. Bottom line, (I believe ) Video courses are never enough and books are long and difficult. So, start with video course and finish it with a book. IMP point : practice while going through the whole process.