chmod command
 

How can i add access for to users to 1 file/map. Do i have to add these accounts into one group, and allow that group to rwx that file? I dont want to change the ownership of the file, and i dont want every people to have access to that file. Do i need to make a group for those to, or is there some other ways?

yes, the best way to achieve this is to create a group and assign permissions to this group.

groupadd - to add group
usermod -G groupname username - to add user to the new group.

chgrp groupname directoryname

yip, i think you gotto make a group of them with rwx-access.

egag