You can find official information on season four of "Lego Ninjago: Masters of Spinjitzu" on the website of its broadcaster, Cartoon Network. Cartoon Network provides videos of previous episodes and episode summaries, as well as broadcast schedules. You can also find additional episode information on iTunes and IMDB.
iTunes provides summaries for each episode of "Ninjago" season four and lets people download episodes. IMDB gives more detailed information about each episode, such as voice actors and production company details.
"Lego Ninjago: Masters of Spinjitzu" is a cartoon based on the Lego Ninjago toys. Season four began on Feb. 23, 2015, and has 10 episodes total.