apt on amd64: question from newbie

[Joao Ferreira gmail <joao.miguel.c.ferreira@gmail.com>]

Hello all,

I've recently installed debian on amd64 from a amd64 NETINST iso.

Maybe I'm a bit confused, but... I'dd like to know if I need to edit my
apt sources.list in order for apt to fetch de amd64 packages instead of
the "standard" i386 packages...

I've noticed that there are amd64 specific .deb packages.... but I don't
now if apt-get/synaptic/etc are "smart enough" to use the amd64
repositories.... or must I edit the sources.list...

thank you

Joao

PS: my current sources.list (I did not touch it after install;)

# 
# deb cdrom:[Debian GNU/Linux testing _Squeeze_ - Official Snapshot
amd64 NETINST Binary-1 20090429-03:20]/ squeeze main

#deb cdrom:[Debian GNU/Linux testing _Squeeze_ - Official Snapshot amd64
NETINST Binary-1 20090429-03:20]/ squeeze main

deb http://ftp.pt.debian.org/debian/ squeeze main
deb-src http://ftp.pt.debian.org/debian/ squeeze main

deb http://security.debian.org/ squeeze/updates main
deb-src http://security.debian.org/ squeeze/updates main

PS2: dpkg tells me I only have the amd64 kernel.... nothing else :)
dell-sc440:/home/jmf# dpkg --list | grep amd64
ii  ia32-libs                            2.7
ia32 shared libraries for use on amd64 and i
ii  linux-headers-2.6-amd64              2.6.26+17+lenny1
Header files for Linux 2.6-amd64
ii  linux-headers-2.6.26-2-amd64         2.6.26-15
Header files for Linux 2.6.26-2-amd64
ii  linux-image-2.6-amd64                2.6.26+17+lenny1
Linux 2.6 image on AMD64
ii  linux-image-2.6.26-2-amd64           2.6.26-15
Linux 2.6.26 image on AMD64
dell-sc440:/home/jmf#