I am trying to learn more about car engines but for the life if me can't find good illustrations of how some of them look (specifically a 2013 Nissan Juke) where do you go to get information and illustrations to get an accurate view?
As a starting point you could do a search, say on Google, for something like "2013 nissan juke engine" – then in the results click on Images (at the top of the window under the address bar). That should get you headed in the right general direction.
You could get more specific by adding specific components that you'd like to see or by including a process that you're interested in. For example, crankshaft or replace timing belt.