As a minimum:
Save and update.
If you have a particular need, you can add -src, -dev, and also unsupported PPA's etc (at your own risk).
My sources.list:
Code:
# deb cdrom:[Debian GNU/Linux 7.0 _Kali_ - Official Snapshot amd64 LIVE/INSTALL Binary 20130327-17:54]/ kali contrib main non-free
deb http://http.kali.org/kali kali main non-free contrib
deb-src http://http.kali.org/kali kali main non-free contrib
deb http://http.kali.org/kali kali-dev main contrib non-free
deb-src http://http.kali.org/kali kali-dev main contrib non-free
deb http://security.kali.org/kali-security kali/updates main contrib non-free
deb-src http://security.kali.org/kali-security kali/updates main contrib non-free