Directory for my LaTeX class and style files

I have an Ubuntu installation and wanting to insert class and style files so that they will be picked up by texhash. Where do I put them?
My system denies me permission (is this a consequence of texlive or my configuration?) to add subfolders to texlive and texmf folders, and texhash does not seem to recognise the directory in which I stored them.
I have also tried to amend the ls-R file directory, but permission is denied.
Alternatively, how can I change the permissions on either creating subfolders or editing ls-R?

John