[OSCOM] How to get oriented ?

Hallo everybody,

 I'm a newbie both in this mailing list and in open source.

I take care of IT in a small company and my developmente skills are a bit
out of date (RPG, AS400, etc.)

I do believe that my company would greatly benefit from the implementation
of some functions (listed below) and it seems to me that many ingredients
can be  found in the universe of the opensource : unfortunatetly it is very
hard to me to get oriented among packages, platforms, languages, etc. : if
anyone could help me in getting some general orientation I'd be very
greatful !!

The very best for me would be - of course - a solution built assembling
existing softwares without any code writing (WHICH LANGUAGE ??? HOW LONG ARE
THE LEARNING TIMES ???)

Here follows the list of the functions that I'd like to implement (today we
just have a Windows domain with some shared folder) :

1.	publishing inside the company (like in an Intranet) folders and files
among small groups of users grouped by argument, by department etc.
2.	publishing links to some Excel macro that extract data from our AS400 ERP
3.	creating electronic forms in order to manage several processes
(purchasing, vacation requests, etc.)
4.	managing the many steps of approval of the documents described above
(workflow style)
5.	possibly (not compulsory) use the same Users, Groups, etc. of the Active
Directory domain

Any contribution or suggestion will be really precious !

Thank you in advance

Andrea Zucconi