Google is your friend. Search for topics like RV Driving School and you will find videos, books, and instructors. I ordered a book online which was quite helpful (unfortunately it's over at the storage area in the vehicle or I would tell you the name of it!). I also looked at a number of YouTube videos which were quite helpful. One of them even showed how to parallel park the coach.
DW and I went to an empty parking lot several times and practiced various close maneuvers. It helped that I have a set of orange traffic cones so we could set up a practice range.
One really helpful hint I picked up was that it's easy to maintain a centered lane position by visualizing my right foot being pointed at the "oil slick" in the center of the lane. That way it's easier to keep my eyes up and maintain the big picture than when I try to line up the outer lane line ("fog stripe") with the corner of the windshield, as one source suggested.
We are also fortunate to have a rear view camera. Using that, and getting used to using the mirrors, makes maneuvering our coach pretty easy.
I do find that I'm learning more every time I drive, whatever vehicle I'm using.
--Tim C.
Park Forest, IL