I've just downloaded a texture pack from David Revoy, which are simple jpeg images when I unzip the folder. Can someone please explain how I add these to Krita. When I go to the resources management options I don't see a folder for textures to copy & paste them into?

Under "manage resources", there should be a button labeled "import patterns". Just navigate to the folder you have unzipped the patterns into and import them here. They'll appear in the list of patterns if you open the pattern docker. In the pattern docker, you can also press the folder icon to import patterns.

Ah, so they go in patterns. Thank you. It was the 'textures' label that confused me.