Free charting/planetarium software

One printable star chart that I have found interesting is at
http://www.cloudynights.com/item.php?item_id=1052

Another more interactive simple charting program is at
http://www.philharrington.net/tuba.htm

For a really deep, printable atlas, there is triatlas at

http://www.uv.es/jrtorres/index.html

If all you need is a monthly one page chart,
http://www.skymaps.com/

For planetarium programs, one of the best free ones find more at
Cartes du Ciel.
Hallo Northern Sky,
Celestia, and
Stellarium are also not too bad.