This guide is written for Samba3 as that is what I have on my system. Samba4 does not need a system user for every samba user.
apt-get install samba
The sambaconfiguration file is located in /etc/samba/smb.conf
An example block for a share:
[Storage] path = /storage browsable = yes guest ok = no read only = yes write list = kradalby valid users = kradalby meepo
Note: This block contains overlapping settings, do not, for example, use writable with write list.
To add a user in samba3:
smbpasswd -a username
To add a user in samba4:
samba-tool user add username
Samba is configured by default not to follow symlinks because of security. If you want to activate it still, add the following to the [global] section.
follow symlinks = yes wide links = yes unix extensions = no