Oracle created a new access point to documentation and basic tutorials, Oracle Help Center. It's https://docs.oracle.com/ .It has a nice, friendly interface. I like it.
There is a link to help video.
Easy search interface:
Now we have the documentation and some tutorials in the same place https://docs.oracle.com/cd/E28280_01/nav/bi.htm:
Files can be directly downloaded without opening them in HTML.
Beyond the regular documentation there are some nice tutorials. A partial list is bellow.
Here is an example:
I like the new look.