CMYK in photoshop? (really frustrating)?

So for my school yearbook, the editors told me to use CMYK mode in photoshop to make the pages (if i use RGB the colours will come out funny).

Anyways, when I add a picture to the canvas in CMYK mode, the colour changes a bit? Is this supposed to happen?

When it's printed, will the colour go back to original or look like what it looks like in the CMYK mode.

And is it okay if I work in RGB and then convert everything to CMYK at the end. (is there gonna be image quality loss etc.)

And if I DO convert the RGB to CMYK later on, will it look like the RGB when I print it?

CMYK in photoshop? (really frustrating)?trojan

If the editors want cmyk, you should work in cmyk, as this is how they want to print it, otherwise the results are totally unpredictable.