pxe install

install and/or configure dhcp3-server
(if you already have dhcp configured you may just add "filename "pxelinux.0";" to the conf.
my /etc/dhcp3/dhcpd.conf:

ddns-updates on;
option domain-name "vstrom.local";
option domain-name-servers 192.168.0.2;
default-lease-time 86400;
max-lease-time 86400;
authoritative;
log-facility local7;

# vstrom
subnet 192.168.0.0 netmask 255.255.255.0 {
        option domain-name-servers 192.168.0.2;
        option domain-name "vstrom.local vstrom";
        option subnet-mask 255.255.255.0;
        range 192.168.0.50 192.168.0.59;
        option routers 192.168.0.1;
        ddns-update-style ad-hoc;
        filename "pxelinux.0";
        next-server 192.168.0.2;
}

install tftpd-hpa
create /tftpboot and edit /etc/default/tftpd-ha

#Defaults for tftpd-hpa
RUN_DAEMON="yes"
OPTIONS="-l -s /tftpboot"

Get the netboot files:

lftp -c "open http://archive.ubuntu.com/ubuntu/dists/intrepid/main/installer-i386/current/images/; mirror netboot/"
mv netboot/* /tftpboot
rm -r netboot

If you only want Ubuntu install you can stop here.

Otherwise:
Make a dir for ubuntu and copy the files there

My /tftpboot/pxelinux.cfg/default:

DISPLAY boot.txt

DEFAULT thin

LABEL thin
        kernel ltsp/i386/vmlinuz ro
        append initrd=ltsp/i386/initrd.img

LABEL hardy_install
        kernel ubuntu/hardy/i386/linux
        append vga=normal initrd=ubuntu/hardy/i386/initrd.gz -- 
LABEL hardy_cli-expert_install
        kernel ubuntu/hardy/i386/linux
        append tasks=standard pkgsel/language-pack-patterns= pkgsel/install-language-support=false priority=low vga=normal initrd=ubuntu/hardy/i386/initrd.gz -- 
 
LABEL intrepid-live
        kernel ubuntu/intrepid-live/casper/vmlinuz
        append root=/dev/nfs boot=casper netboot=nfs nfsroot=192.168.0.2:/media/intrepid-live file=preseed/ubuntu.seed initrd=ubuntu/intrepid-live/casper/initrd.gz --

LABEL intrepid-rescue
        kernel ubuntu/intrepid-live/casper/vmlinuz
        append root=/dev/nfs boot=casper netboot=nfs nfsroot=192.168.0.2:/media/intrepid-live initrd=ubuntu/intrepid-live/casper/initrd.gz single --

LABEL gparted
        kernel gparted/vmlinuz1
        append initrd=gparted/initrd1.img boot=live union=aufs noswap noprompt vga=788 fetch=http://192.168.0.2/filesystem.squashfs

LABEL grml
        KERNEL grml/linux26
        APPEND root=/dev/nfs rw nfsroot=192.168.0.2:/media/grml boot=live lang=us nomce quiet apm=power-off nodhcp noprompt noeject initrd=grml/minirt26.gz vga=791


PROMPT 1
TIMEOUT 0

And the /tftpboot/boot.txt

=============================================
Thin Client (Ubuntu 8.04 Hardy Heron)
  thin

Install Ubuntu 8.04 Hardy Heron 
  hardy-install
  hardy-cli_expert_install
  hardy-rescue

Ubuntu 8.10 Intrepid Ibex (Alpha)
  intrepid-live
  intrepid-rescue

Tools
  gparted
  grml

Now to add systems;

Ubuntu 8.04 Hardy Heron install:

...more to come about adding the the systems to the tftp server