Linux users and/or developers?

[slapo]

At the moment, I would like to set up a dual boot system with Linux and Windows 11, so I would first need to partition the disk.
Do you have any reliable guides to recommend or useful tips to follow before I begin?

You could resize the partition Windows is on, but if that goes south, you could end up corrupting that installation or the partition as well.
However, if you have backups and wouldn't mind reinstalling Windows if it wouldn't work out, go for it.

If you can spare the money, going with @pjgh's suggestion and getting a second drive would probably be easier.
You could also install Linux on a portable drive, although performance might not be as good as when it's on an internal drive