best way i know how is to do a search for that year/make then on the right side of the page, you'll see a link for "Update your collection". After clicking on that, you'll see a drop down menu.. you can choose to Add all of those cards to your collection or just go down and check them off individually. The drop down will provide other options as well.
you won't be able to add the pack, without knowing whats inside, but if you have a box (that contains the complete set) you can do it, other than that without know whats inside i don't think there are options avail for that.
hope that helps some.