I am a GIS n00b. Our company has ArcGIS 10 desktop, and since it is multi-user license, I was allowed to install on my computer. I was given a copy of "Getting to know ArcGIS desktop" but it is for ArcGIS 9. Are the two versions so different that I should just get myself the latest copy for 10? ESRI sells it for about 70 dollars so I'd like to not spend the money, but I'd also like to learn the system as well as possible.