OK, let's start from the distro:
If you are newbie on linux probably Fedora Core 5 is a good call; there is nothing wrong with Debian, (actually I think it is the best distro) yet the install process could put you off linux very quickly.
Second question:
Yes, you may leave the box accessible only from LAN.
In order to have full control on your linux box from windoz these softwares are a must:
PuTTY.exe -- ssh terminal
pscp.exe -- windoz implementation of scp
VNCviewer -- remote desktop software
winscp -- optional if you are lazy and do not want to use the dos prompt to move files. uses a windows commander like interface.
All above windoz software is freely distributed, all excluding VNC are also open source.
Configuring SAMBA is not difficult and will give you access to cifs shares on your linux box using windoz network neighbourhood.
Where to find reference guides:
(The Linux Documentation Project)
Where to find human tutorials:
(follow the linux networking link)
If you get stranded, this forum is the best place to seek help.
Cheers
QatQat
Life is what happens when you are making other plans.