Sharing files from PC to Mac through Bootcamp

Hi there

I'm running Windows 7 through Bootcamp on my MacBook Pro and can't access the files. I use the Mac most of the time but as a trainee teacher I have to use the PC in schools :-/ and need to access both systems.

I can see the PC files in the finder but they are all 'read only', I can copy them over to the Mac but I can't copy anything from the Mac to the PC.

Any ideas?

Thanks