Here’s the 5 minute tutorial.
I’m favorably impressed by the tutorial site mentioned above. Bare simplicity is an excellent introduction. On the other hand, the huge volume of information from IBM covers (almost) every conceivable detail. It takes time to find the nuggets that can be useful in the beginning.
Two good ones from there for beginners are Introduction to the IBM System i family.
I suspect that any one of us who visits the links pages there will find something they want to review.