Can't share files between users.

you will need to create a group and add both of your users to the group, you can then give read and write access to the group, permitting both users access

e.g. (2 users foo and bar, want full access to /home/foo/share)

sudo groupadd share_group
sudo useradd -G share_group foo
sudo useradd -G share_group bar
sudo chown :share_group /home/foo/share
sudo chmod -R g+rw /home/foo/share

Now the group share_group is the group owner of the folder, the folder is still owned by foo but has granted access to the folder via the group (g+rw). You can even have folders in the share folder that are not accesible to the group and you can simply run:

sudo chown -R foo:foo /home/foo/share/secret

so foo is now the owner and group owner of the folder, bar is not a memer of the foo group (only foo is) so bar will not get access.

Almost got it. Sticking with your example, bar has access to files in the share folder but not folders. foo cannot access any files or folders added by bar. Thanks for the help so far!

try:

sudo chown -R :share_group /home/foo/share

forgot the -R to recursively set the permission

bar just lost access again. I should have mentioned this before but I put the share in /home (/home/share) does this make a difference?

Thats fine, it can be anywhere at all, as long as correct permissions are in place then it can be accessed.

Can I see which permissions are in place?

"Can I see which permissions are in place?"

Right click on folder you want to see permissions >properties>permissions.You can have advanced GUI permissions if you type in terminal

gconftool-2 --type bool --set /apps/nautilus/preferences/show_advanced_permissions True

After that look for permission of desired folder.

sure:

ls -la /home/share

will show you what permissions are active.