Individual profiles..

Ive been learning alot from this site it really helpful...

My adviser was suggesting that i use a program to have each user on each computer have a log on system... other words all the computers would be able to log on to the system using their profile... my guess is that it gonna be very hard to do that..

The reason is that each user is able to see the docs of the other when they use the set profile (this profile is a limited so each user is not allowed to create a user profile except admins)... so i think it's an application software that I'll need tho.

Im assuming you need something more user definable than Windows "User Accounts".
Have a look.
http://www.tricerat.com/solution/profile_management

universal concept:- EVERY user needs a unique user/password. NO Login ID should ever be shared between multiple users.
If a common set of files are needed to be R/O or R/W, then place them on a Shared Folder elsewhere and mark the permissions as appropriate.

Issues:-
Shared Logins have impossible audit as who did what to whatever and when.
As an administrator, this is an absolute requirement. If a Shared Account gets compromised, then there's no accountability.

Investigate using Remote Profiles. The user logs onto the server and the specific profile is imported from the Windows Server, allowing anyone to log-on anywhere.