Sorry I am really new to "network" things. :-D

There is a task like:
previously, the program does a lot of IO and calculation and shows them
out. All on the same machine in one piece code. Since the IO and
calculation is very very time (and memory) consuming, now it is asked
the possibility of doing it in the "client-server" way:

So I hope it can work like this:
1) client sends server of "job ABC": which files to load and how to
calculate them and where to save them. Please note the files are never
transfered over the network. They are always read/saved on the server
side.
2) server side does the job (IO, calculation) and when done, sends
something back to the client to inform the client "job ABC is done".
3) then the client can retrieve the results from server for display.
(The results are just some numbers so should be fast over the network).

For this application, which architecture / packages / classes should we
use? It would be very useful if someone can write a "pseudo" code so
that I can know which methods to use are best in terms of efficiency as
well as easy to code. And a set of keywords so that I can google them
for the details. Also, is the simple examples from sun's site:
http://java.sun.com/docs/books/tutorial/networking/sockets/clientServer.html
good for real applications such as the one I need? (I am guessing a lot
of "hello world" applcations are really not that good in real world)

As the above task, any pitfalls, shortcuts, known bugs or issues, or
anything else that should pay special attention?

Thank you a lot!