To see the permissions on the files in a directory type the following:
# ls -l
Then you will get an output similar to:
-rwxrwxr-x 1 Gauge LANparty 3330747 Mar 9 2002 SetupCloneCD4202.exe
There are three permission groups and three permissions for each group. The permissions are:
r = read
w = write
x = execute
Full permissions are:
-rwxrwxrwx
The first "group" of rwx is for the owner, which on the example I showed you is me, Gauge. The second group of rwx is the permissions for the group the file belongs to, in this case LANparty. The third rwx is for "Others", which includes anyone not in the first two rwx's. If the r, w, or x is present, the permission is granted. If there is a - in its place, it is not granted.
when you chmod a file, you set the permissions. you give it three numbers from 0-7. Each number sets the permissions for a group. The permissions are set using binary code for the numbers given... thus
0 = 000 = ---
1 = 001 = --x
2 = 010 = -w-
3 = 011 = -wx
4 = 100 = r--
5 = 101 = r-x
6 = 110 = rw-
7 = 111 = rwx
So, if you wanted to give everyone full permissions to a file, you would use the following command:
# chmod 777 file_name
Sorry if I didn't explain it well enough. Tell me if there's any confusion and I'll try again.