Counting the number of galaxies in the Hubble Deep Field
multiplied by the angular extent of the sky estimates about
100 billion galaxies within our observable horizon.

Here is a better source of information that is typically
found on TV.

Ned Wright's Cosmology Tutorial
http://www.astro.ucla.edu/~wright/cosmolog.htm
http://www.astro.ucla.edu/~wright/cosmology_faq.html

WMAP: Foundations of the Big Bang theory
http://map.gsfc.nasa.gov/m_uni.html

WMAP: Tests of Big Bang Cosmology
http://map.gsfc.nasa.gov/m_uni/uni_101bbtest.html

-Sam Wormley
http://edu-observatory.org/eo/galaxies.html