How I find users that read/write/delete in a directory ?

I want to know the user (name, IP, something) how read/write/delete in a particular directory

I think you are asking about permissions eg
drwxrwxrwx
which broken down means
d this is a dir file
rwx u - user/owner has read/write/execute
rwx g - group access is read/write execute
rwx o - others/world has read/write/execute

See the chmod cmd to alter permissions
eg
chmod u-x filename
means remove x (execute) perm for user (aka owner)
see here http://rute.2038bug.com/node17.html.gz for more info, in fact that on-line manual is invaluable, you should bookmark and read it.

I'm not sure I understand what you want. Anyhow in a terminal window you can type:
ls -l
to get a list of files/folders and their userrights. I.e.
drwx------ 3 lamename users 4096 2007-10-15 18:35 Desktop

In a directory you only don't have read/write/delete, it's read/write/execute. read is to read it's content, write is to modify the content of the folder (Create and delete files/folders. So if a user got write access to a directory the user can actually delete files, even if the user doesn't have any access to the actual file.) and execute, to be able to open the folder (cd to it) read 'man chmod' to understand the userrights better.

If you use a GUI, you could right-click on the folder and click on properties or something.. I don't use it to often, so I really don't remember.

Is a directory mount with samba

I what to know in any moment the user (or users) that read/write/delete in this directory .I think I have to make some log file to colect informations but I don't know how.