You can download the user manual for the Canon EOS R in PDF format here. Unlike the Canon R5 and R6 there is unfortunately no online version of the manual available.
David Busch’s Canon EOS R Guide
If you are looking for a nicely formatted book, popular camera guide author David Busch has published his Canon EOS R Guide to Digital Photography which is available on Amazon.
Canon RF Forum & Facebook Group
If you are looking for further help and advice on Canon R Series cameras or would simply like to share your photos and videos, then please head over to our friendly RF Forum. If you prefer Facebook then we also run the Canon RF Shooters Group.