Objects
To make your objects work you'll have to extract the zip-file, and put the files into: MyDocuments/EAGames/TheSims2/Downloads If you don't have a download folder, you can simply create one.
Recolors
You'll have to install the Color Enable Package (CEP) to make some of the recolors work.
Terrains
Extract the zip-file to this folder: MyDocuments/EAGames/TheSims2/SC4Terrains
Collection Files
The collection files have to be placed into MyDocuments/EAGames/TheSims2/Collections
Donating
Make a donation with paypal and you will automatically be redirected to the downloadpage of the set you donated for.