I would suggest starting off with Mandrake or Suse, or other distro's that have graphical installers and wizards to help you set up and configure.
I don't do spreadsheets/database, but I'm pretty sure OpenOffice (free) or StarOffice (not free) can handle that.
There's a very good site here
about getting Hebrew to work in Linux.
There is plenty of information on the internet about Linux networking. Here's one page
to get you going and this
is a general Linux beginner site