Describle the driffent geography of north america

That answer would take more than what space and time allows, but I will give you some sites to research on your own.

Since you do not ask if you are looking for the physical geography alone or other, several links are listed.

The Physical Geography of North America (http://www.questia.com/PM.qst?a=o&d=104422899)
Seterra - Learn The Geography of North America and the USA. Free Software. (http://www.wartoft.nu/software/seterra/north-america.aspx)
North America - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/North_America)
Internet Geography @ www.learnontheinternet.co.uk (http://www.geography.learnontheinternet.co.uk/northamerica.html)