Difficult to answer. I gave my best guesses, but the issues that I was running into were:
-I run a multiplanar campaign that theoretically touches all campaign settings. We've already been in a homebrew world, the Forgotten Realms, and Ravenloft.
-I make use of a combination of my own designed adventures, official adventures, and sandbox "create your own adventure by living your life" style of of adventures.
-I found it very difficult to assign numbers to preparation time because most of it is done up front and not on a per session basis. Per session I might spend anywhere from a few minutes to a few hours, but there are many, many more hours that have gone on before a campaign ever started, and with a long campaign it is extremely difficult to parse that out to how much applies to an immediate session.
-For tools, I wasn't sure what kinds were most relevant there, and I listed Realm Works (world database for all of my campaigns and settings, and session journal entries), iTabletop (VTT with rooms, maps, an initiative tracker, dice macros, video, and the ability to play uploaded music to the group) and Teamspeak (quality voice chat and an easy format for sharing files, posting links, and sending private messages to individual players.)
But were I allowed more options I would have also listed a shared spreadsheet (Excel Online) for editing character and party inventory, a local spreadsheet for sorting spells by various factors (it's Ari's, but I rewired it a bit for my needs), digital basic rules and OGL, pdfs of previous edition setting materials, pdfs with material I've created, a text file for keeping track of session information, all of that divided up amongst 2 laptops, physical books, some printed cardstock sheets with important DM references, rules, and tables (like a custom DM's screen, but in loose sheets for ease of access), a printed sheet with condensed PC stats, printed copies of each PC's character sheet (rarely needed, but it comes up), printed sheets with all of the spells known by the party (in PHB format), physical dice, calculator, a physical notepad and pencil for quickly jotting down things to take care of after session, as well as tracking monster hit points and placement relative to characters. And two bottles of water.
Wish I had another computer or a gigantic monitor, and an extra table on my other side.