Well probably the first step would be to create a rosetta stone for them. Encrypt something that will probably be around for for a very long time in multiple languages. I would suggest three religious texts the bible, the Koran, and the Bhagavad Gita.
Follow those by various texts on language, science, math, and history.
Next I would document all the data formats used in the rest of the data.
Then I would include things like all the patents and so forth.
Then store copies of all the data in lots of places. Places like monasteries, castles, forts, national parks, the dry valleys of Antarctica, the tops of the highest non-volcanic mountains of each continent, the Atacama Desert, the great pyramids, several of the Mesoamerican pyramids, Stonehenge, and finally Ísafjörður and Neskaupstaður Iceland. The last two are near the mid atlantic ridge but not near active volcanoes. With the seabed spreading at the mid atlantic ridge that land should be around the longest. Maybe it should be an ongoing project. Every 100 years each of the data stores gets updated.