I'm starting from a clean Ubuntu install, and using this webpage as a reference: http://tails.boum.org/contribute/build/

I made sure I had all the packages listed there installed. When I run "lb clean", I get these errors:

P: Considering defaults defined in /etc/live/build.conf
live-build: unrecognized option '--binary-indices'
live-build: unrecognized option '--package-lists:standard'
live-build: unrecognized option '--syslinux-menu'
live-build: unrecognized option '--syslinux-splash'
live-build: unrecognized option '--syslinux-timeout'

Any suggestions on how I can resolve that error?

It seems you're using live-build 3.x (the alpha version) whereas building Tails requires "live-build from Debian Squeeze", which is version 2.x. Please downgrade.
Comment by Tails Sun 27 Nov 2011 06:07:51 PM CET