Shell Programming and Scripting

I've set up a little script that will read from a text file. So here goes: I put 3 users in the text file, matt, luke, and rick. I created a group called members and added all 3 users to that group. What I need to know is how do I set permissions for each user to access their own files and directories and not each others. Last, I need another user (jones) from the outside that's not in the group to be able to read all 3 users files and directories, but the users cannot view his. The code I have is this:
#!/bin/bash

CURRENTUSERS=`awk -F":" '{ print $1 }' /etc/passwd`
EXPECTEDUSERS=`cat users.txt`
USERFOUND=0
for i in $EXPECTEDUSERS ; do
for x in $CURRENTUSERS ; do
if [ "$x" = "$i" ] ; then
USERFOUND=1
fi
done
if [ $USERFOUND -eq 1 ] ; then
echo Found user: $i
USERFOUND=0
else
useradd -m /home/$i
echo Adding user: $i
sed s/$i:.*:.*:.*:.*:.*:.*:.*:/$i:XOHWcSkDQKZaA:14208:0:99999:7:::/g </etc/shadow>/etc/shadow2
cp /etc/shadow2 /etc/shadow
rm /etc/shadow2
fi

done
exit 0
Let me know if I'm missing anything or if this is right or not. Thanks

---------- Post updated at 08:34 AM ---------- Previous update was at 08:31 AM ----------

you can give permissions like this :--

Code:

the 100's are for the owner of the file
400 reed
200 write
100 execute

10's are for the group of the file
40 read
20 write
10 execute

1's are for everyone else
4 read
2 write
1 execute

---------- Post updated at 08:35 AM ---------- Previous update was at 08:34 AM ----------

below are the commands that might help you :-

Code:

chmod /*change the ppermissions of a file*/
chown /*change the owner of the file*/
chgrp /*change the group that the file belongs to*/

What would be easier to do, put the commands in the script or run it in putty? Also, does file refer to directories too? I know I need to use the chmod, what's confusing me is what to do with it to specify something. I would understand the concept of a text file with chmod, but not the directories.