Once it's done, you can make folders within the Default option on the left side. Then you start up the program and it'll run through it's initial refresh and it'll automatically import your Sims3Packs. What you do is you make sure that the Sims3Packs you want to install are in the normal download location and your mods are in the packages folder (save for overrides and I keep Nraas and any other major fixing mods in a different subfolder within Mods). Patterns and worlds do have to be installed the normal way from what I understand (also the best way to make sure they install properly).
