Questions on Outlook 2010

Where I work, I am the IT guy and so I am looking into moving the company up to Outlook 2010 or MS Office 2010... not sure yet there.

But I do have questions regarding Outlook only... like does (1) CD install on (1) or (2) systems?

If we migrate to Outlook 2010, do we also have to upgrade to MS Exchange Server?

We do not have a "server" but have merely used a CPU with Windows 98 OS to serve as the "post office" for inner-office email. How would the newer Outlook work in this format?

Would really like to speak with anyone who has been through this or has extensive knowledge of Outlook 2010 and how it works with a peer-to-peer network.

thanks.

 

Maybe I need to add more info here...
All the systems here are WinXP (Pro mostly - SP3). We have been running MS Office 2000 and obviously that is WAY outdated, so I am looking at upgrading. Would really like someone to chat with and determine whether it would be better to get just the Outlook 2010 CD or go with the MS Office 2010 package and that way upgrade all components. Also need to know if in this upgrade, would I need to get MS Exchange or other software in order to make the upgrade work efficiently/properly.

Is there anyone on here that is a guru with MS Office/Outlook and is willing to take some time and chat via email with me so I can get a clearer picture of what I need to do to make this upgrade work?

thanks again