tell me digen ... can i say the the way sify iway, or the banks works is a example of "domain implementation"... if it is then yes i am not guy who should try to setup this kind of network... at list for now with this little knowldge..... but also we dont need that one...
Yes.Domain networking is mostly used in entreprises,govt,school/college networks.. the list is boundless.
The reason is quite obvious,managing & maintaining a large lan is somewhat easy from a central location.Although this isnt the only reason.Implementing policies,security,data backup also play a important part.
The reason I gave a overview of domain vs workgroup environment is because right now you should do fine,but later you may want/have to consider it.
Since you mentioned internet access,will all workstations get internet access?
Have you thought about how you are going to carry it out? Router,ICS,Proxy ?
Since now we are talking of the windows family,the process is nearly the same.Check that guide,also a guide by raven for sharing a internet connection.Shoot if you get stuck somewhere.