I have a nice example of the basics of making your own snow at homeat the website: http://snowmakingathome.com However, I have some more links for you...First, snowguns.com is a GREAT forum where you can get online help. The commercial site snowathome.com has some good links such as links to a snowmaking "Chart" showing the proper temperature and humidity needed.
If you'd like to see a story I did on it at Channel 4 in Salt Lake City, go here:
and the link to the Boston Globe article is here:
Snowmaking is rewarding, but tricky. The "quiet" snowmaking highlighted in the Globe is pushing regular household appliances beyond their normal call of duty. The basic idea is to mix compressed air and water with a small compressor and outputting the tiny snow crystals through a tiny nozzle. Then additional wateris throw into this plume of snow using a power washer, and again, a special nozzle.
If the air is dry enough , you can begin making snow when it is as warm as 33 degrees outside, but normaly it should be closer to the mid-20s. :)