Choose a section on the left. From there you can click on the logo's to choose a category.
Click on the thumbnail to see a preview. The preview will open in new window, you may need to temporarily allow pop-ups using the yellow information bar.
From the preview window there will be link to download the sims package(s).
To download a Sims2 package, left click on the download link, and a dialog box will open asking you to save the file.
Save it to your "Downloads" directory in the Sims2 folder. From there, unzip the file, and double-click the package to install it to the Sims2.
Several of the downloads now require The Sims 2 University Expansion pack.