Samba is what Linux uses to connect to Windows - you will need to install it on both the server and your pc.
To connect to your company's mailserver (I am guessing they use Exchange) you will need to enable the webmail option on the Exchange server (you will need a licence to do this) and get Ximian Connector from Novell/SuSE.
In both these cases you will need a friendly admin to do the server work and someone will have to fund the webmail licence.