This shouldn’t really be taken as a guide, or even necessarily recommendations. I figured I’d just lay out the way I approach DMing, and some of the tools I use. If you see something here you like, great. But by no means think that I’m saying this is the best approach. It just happens to be what works for me. Also this more or less applies to most games I run, but most of my examples will have a 13th Age bend just because that’s what I’m currently running.
In general my notes tend to be sparse. Almost embarrassingly so when I see just how much more detailed other peoples notes can be. I’ll include notes of what’s just happened, what I’m expecting to happen, and some details to help me fill in the gaps. People, places, prosible events; as well as a handful of stats for encounters that I can pull from. With icon rolls influence 13th Age, I sometimes have sets of possible encounters depending on what icons are likely to be more involved in the session. At the end of the day, we’re talking about really just a couple brief paragraphs of serious notes, followed by stat blocks. I’ll fill in more details as we play so I can remember what happened, but ultimately my DMing style definitely leans towards improv.
Now for a while Google Docs was one of my primary tools. It’s still used heavily by my players. Digital character sheets are quite convenient and easy to make in just about any spreadsheet tool, but with Google Docs sharing becomes extra simple as well.
These days though for my actual DM notes, I’ve a big fan of OneNote. I keep an RPGs notebook, and there I keep tabs for Reference, Templates, and one for each campaign. Under Reference I keep notes, often literally copied and pasted from the game PDFs that I’ll find handy in the game. It makes it pretty easy to just select a chart or table and put that directly into the document for reference. Under Templates I keep tables, typically for monster stat blocks ready for use in the campaign notes. And under the campaign I keep a page to keep track of the individual characters, their basic stories, current magic items, and soon. As well as a page for each session. Here’s where I keep my couple paragraphs and stat blocks. All of this keeps me pretty organized. OneNote also has the advantage of being freely available on Windows 8, Mac OS X, and via web interface.
I’ve also grown into the habit of keeping a combat tracker spreadsheet. My 13th Age one has grown some extra features, and I still plan to add more. The most basic need is to be able to mark the combatants initiative so I can quickly sort them. But at this point I’m also keeping track of the enemy health, the damage they’ve taken, and it automatically shades in red when the enemy is staggered, something I need to know for certain abilities. I also keep columns to keep track of PC engagement, as well as any other notes I may need like ongoing status conditions. I’ll link to it here. In the future I plan to also add columns to keep track of mooks automatically. (In 13th Age, Mooks are a sort of group mob. They share initiative, and HP, but act separately. So there’s a need to know how many are alive still, as they get that many turns on their tick.)
That pretty much covers it as far as notes and technology. Aside from that, I just try to keep things fun for my players.