hi snowee ok i will give you a step by step guide on how to do a mod folder/packages folder
1 - click on documents
2 - open up Electronic Arts
3 - open that folder
4 - right click in a space and click on new in the drop down list
5 - name this folder Mods
6 - open this folder
7 - again right click in here to make a new folder call this one packages
8- this is where you will put your downloaded sims3 packages
hope this helps