Nice Article ncryption.
I am purely Microsoft based and thus if you are used to M$ applications you may find that Linux, Suse, BSD etc. are a little out of your league without some research.
To add to this article. If your company is mostly Microsoft orientated my suggestions would be as follows:
Smallish company:
Workstations: Windows XP Pro is the way to go, quick, reliable and not too resource hungry. Win XP Pro has definately put a foot in the production market as a reliable and fairly cheap OS to implement.
Servers: Windows 2000 Server or Advanced server is a great starting point, both are very reliable and fairly easy to implement and use. With these platforms you can do almost whatever server requirements your network requires.
Building a server with a Windows 2000 backbone will give you functionality to run the following production applications for various tasks.
Email: Production - Exchange 2000 is the step between 5.5 and 2003, it gives you almost all of the functionality in 2003 and is the mainstream Exchange solution for most business's out there. Exchange 2000 will provide your network users with Email and Outlook integration. You are also able to run your Email suite outside your internal network that can be accessed via OWA (Outlook Web Access) from remotely. Exchange is a powerful (yet easy) apllication to configure and maintain.
Database: MSSQL Server: SQL is the direct oposition to Oracle. both of these database solutions are fairly expensive although Oracle licenses can boost the overall price of the software into the millions. SQL is a powerful solution that provides easy administration of Databases. Oracle is quite a bit more complex than SQL and more powerful in certain instances although SQL will do a fine job at a decent price.
Innternet firewall: Microsoft ISA Server (Internet Security and Acceleration server) ISA server is a software based firewall solution from Microsoft. It is robust and fairly easy to install as with most Microsoft applications the GUI is informative and self explanatory. ISA can accomodate for many different types of firewall protection. It has functionality that encorporates A DMZ should you require and can support ADSL connections if setup correctly. Although I am a strong believer in OpenBSD as a firewall solution (a little contradition in this post

) ISA has reporting features and a GUI that makes it informative and easy to use to people with limited knowledge of protocols and Security.
SUSUpdate: (Systems Update Server) this ingenious application hosts all Microsoft updates and publishes them to the machines within your network. It's like having your own Windows Update Server, how it works is as follows: SUS will connnect to Microsoft and download all the updates you choose for the applications and operating systems within your network. After the updates are downloaded and marked for update the SUS server will automatically keep the machines in your network up-to-date without having them connect and update using more bandwidth.
Active Directory: There is vast features in Active directory that can be added and I will try and add from time to time. The basics of Active Diirectory is to store your User accounts. Active directory connects into Exchange and thus you can administrate alot of Exchange features through active directory. Active directory functions as a repository for User accounts, Exchange Accounts embedded into the User accounts and a repository for adding, editing, deleting and ammending User accounts. One of the best features in Active directory is GPO (Group Policy Objects) More to come on those.....
Ncryption I would like to keep this as an open Article whereby we can constantly add information to the relevant groups and applications?
More to come guys.