http://en.wikipedia.org/wiki/Igloo
A wikipedia entry about igloos. Specifies who uses igloos as shelter as well as where they can be find. Talks about the practical and cultural functions of igloos. Also tells you how to make an igloo!

http://www.howstuffworks.com/igloo.htm
How igloos work! Goes into more detail than the wikipedia entry about the insulating properties of igloos.

http://en.wikipedia.org/wiki/Quinzhee
Wikipedia entry about Quinzhee, an structure made out of hollowed out snow rather than packed blocks of snow.

http://www.nfb.ca/enclasse/doclens/visau/index.php?mode=view&filmId=11340&language=english&sort=title#
Ten minute footage of Inuits making an igloo. Presented by the National Film Board of Canada (made in 1949)

http://www.uwgb.edu/dutchs/PETROLGY/Ice%20Structure.HTM
The molecular structure of ice!

http://en.wikipedia.org/wiki/Snow_cave
Wikipedia entry about snow caves-another form of “ice shelter”. “A snow cave is a shelter constructed by mountain climbers, winter recreational enthusiasts…”

http://www.psychovertical.com/?snowshelters
http://outdoorswithdave.com/camping/building_a_snow_cave.htm
Building snow holes/caves for mountain climbers.

http://www.traditionalmountaineering.org/FAQ_Snowcaves.htm
Dangers of snow caves

http://pbskids.org/nova/denali/snowcave.html
Pictorial diagram of a snow cave.