Have you seen the Time Traveler Cheat Sheet?
That alone will get you everything you need to kickstart a medieval society up to industrial (although most of it will be very difficult to achieve straight away). The rest can be figured out with research: simply knowing a task is possible can be enough to generate the means to solve it (e.g. an atomic bomb can be worked out with only a high school education and access to materials).
From there, download the text-of-articles-only copy of Wikipedia (a mere 43 GB uncompressed). Most of which will be useless (articles on plants, animals, people, places, and historical events which have no bearing on your task) but the remainder will provide a fairly solid background on useful topics and easily searchable. While it might not go into sufficient detail to act as a blueprint, it should provide the cursory knowledge which your wizard contacts should be able to learn from and devise their own solutions.
Follow that up with a trip over to http://www.survivorlibrary.com/ and download the stored resources there, which cover a variety of topics and generally used as a resource in case Earth bombs itself back to the stone age. It is unfortunately mostly ORC'd pdfs (not very compressible), but does fit on 31 DVDs (or 6 BluRay) which are available for purchase (that is: I don't see a 'download all' link, but I do see the DVDs for purchase which gives an indication of size).
A modest tablet computer and recharge method (e.g. solar) along with an external battery (charge the battery with the solar, charge your device from the battery) or two will be sufficient material resources to store your collective knowledge. If you can, bring a bunch, rather than forcing everyone to cluster around a single screen.
The first thing you'll want to do is devise other methods to recharge your tablets so that you aren't confined to the dwindling resources you brought with you (solar cells will fracture, cables will fray, things will get damaged). Which you should be able to do with the time traveler's cheat sheet alone. Thin copper will will likely be your first challenge, and while easy to manufacture in quantity with the right tools, making those tools and finding a supply of raw ore will be difficult.
A good wire draw plate may be advisable to locate and bring with you as well, as it is light and easily transportable and absolutely essential to the production of wire, as well as some strong neodymium magnets. Both will speed the production of your first generator (necessary to keeping the devices regularly charged!) and will be very difficult to produce otherwise.
you can't have all the knowledge of your world in your pockethave these wizards never heard of phones? $\endgroup$