How a Helium Balloon Works
Helium balloons tend to fascinate adults and children alike (and it's not just the Donald Duck voice thing, though that is a big draw). Learn all about helium and why it floats!
http://www.howstuffworks.com/helium.htm

Löwener Vacuumservice
We build helium leak test machines, helium leak detection systems and special helium leak detectors
http://www.lowener.se/e/

Superfluid Helium
A Site on the Properties of Superfluid (He II, Superfluid of Helium)
http://www.yutopian.com/Yuan/HeII.html

Helium Dewar Level Chart
If you get a Cryofab Dewar (Liquid Helium) with out the handy dandy chart, here is the actual charts diect from Cryofab.
http://www.cryofab.com/html/manual_2a.htm

It's A Gas
It's A Gas provides helium tanks for purchase, refill and rental as well as balloons, professional decorating, and imprinted balloons through a mobile service nationwide.
http://www.homestead.com/heliumtanks/

LANL: Helium
History, sources, properties, and uses.
http://periodic.lanl.gov/elements/2.html

It's Elemental: Helium
The Element Helium - Basic Physical and Historical Information
http://education.jlab.org/itselemental/ele002.html

Especiál Gas Inc.: Helium
Helium - He - Helium is a colorless, odorless and tasteless gas. It is present in dry air in a concentration of 5.24 ppm by volume. Used extensively in the welding industry as an inert sheilding gas in arc welding. Used as a leak detector and as a carrier in gas chromotography.
http://www.c-f-c.com/specgas_products/helium.htm

Corrosionsource.com: Helium
History, sources, properties, isotopes, and uses.
http://www.corrosionsource.com/handbook/periodic/2.htm

Helium Three
The site where participants can debate on the issue of going to get the He3 from the moon.
http://freewebs.com/helium3