As I keep mentioning, I'm a buyer of games in electronic form these days. Not entirely exclusively, but close. One of the things that can now make or break a sale for me, and also make or break a recommendation that others purchase a book/file, is how well it's bookmarked. But what consitutes good bookmarking? I'm glad you asked that! What I'm going to do here is show some examples of what I regard as okay bookmarking and really good bookmarking, with a few comments.
First of all, though, let me illustrate the worst kind of bookmarking, which is to say, none at all. This is HeroQuest 2nd edition, a game I love very, very much. But this is why I'm not doing very much with it for my personal use these days: finding things is a drag. I could, over time, assemble my own bookmarks and annotations, but the fact is I don't want to. At 132 pages, HQ2 isn't as long as, oh, say, the vast majority of White Wolf books I own, but these days they pretty much all have at least rudimentary chapter-level outlining and bookmarking, and everything new has much more detailed ones. It's a shame, but honestly, groping for text is about my least favorite part of gaming.
It's not like this a problem unique to HQ, of course. I keep seeing a fair number of promising releases which don't have any bookmarking at all. It's not my place to sit and guess at market shares and what fraction of the readership cares about what. Thank goodness. I like being just a citizen of the gaming polis. But I know that the concern I'm expressing here certainly is a very common one among people who're reading on tablets, and also on laptop and desktop machines. It's easier/quicker to search for text with a full keyboard and mouse interface, and scrolling through thumbnails can be surprisingly handy, but there are no circumstances involving online reading where a good set of bookmarks is a liability.
Next up, an example of okay bookmarking. This is Monsterhearts, one of the rapidly growing family of games tweaking Apocalypse World for their own purposes. As you can see, it includes the chapter numbers and titles, and Joe Mcdaldno gave each chapter a clear, useful title. So you can get in the vicinity of where you're going pretty rapidly, and then you can rummage around a few pages to find what you're looking for. It works, particularly given the playbook structure of the AW family of games, where so many crucial mechanics are in class-specific spreads available separately. But it'd be okay for games without that advantage as well, as long as the chapter names remain useful. (That's not a given. I, um, have committed some pretty obscure chapter titles in my time, and I'm not alone in that. I was relying on table of contents and the then-WW-standard “here's what's in each chapter” part of the introduction. I never had this kind of usage in mind. My bad, along with others'.)
Naturally, the more detailed and expansive each chapter gets, the less help this kind of thing would be. Monsterhearts is 160-odd pages long, with a generous, uncrowded layout. Trying to make your way through something like D&D spell lists with just chapter-level entries would get slow and tedious in short order.
Now for an example of bookmarking done well. This is from Blue Rose, John Snead's foray into romantic fantasy roleplaying developed by Steve Kenson. It bears noting here that this is from 2005, well before there was any tablet market to speak of: it's just that the Green Ronin crew laid things out in a way that made sense for the desktop/laptop PDF market of the time and that continues to make sense as platforms evolve.
It's not the most detailed breakdown imaginable—there could be sub-entries for each of the six abilities, for instance. But what we have here is going to suffice for very quick look-up almost all the time. Everything is clear, and you're never going to be more than a page or very few away from what you're after by clicking on the relevant entry.
Since I am not a very technical person, I don't know what it is that some layout people do to make tables of contents like these indent by level of sub-heading on the iPad. I know that it's something they do, that not everyone does, because I've seen my share of flat, everything-at-the-left-margin outlines. As long as the details are there, that's okay, but the indentation helps a very great deal in quick, coherent navigation. Some people's minds parse undistinguished lists without trouble, but my mind isn't one of thsoe; I welcome all hte clues I can get.
This, then, is what I want to find when I check the bookmarks of a newly acquired game in electronic form. Nor is this just a matter exclusively of PDF usage!
Here, for instance, is Diaspora, Brad Murray et al's Fate-based game of post-Traveller hard-ish sf, as seen in Apple's iBooks app. You may have problems reading the details because I shrunk it down a bunch, but you can see the hierarchical layout. The headings are very brief—Diaspora has no poesy of the directory—but it's all clear, and the progression from “Clusters” to “systems” to “linking systems” to “construction sequence” will help you get where you're going. Each line is a hyperlink, though that's not obvious from their coloring or anything; it's something any iBooks user will find out in short order.
Kindle files can have similar formatting. Likewise with HTML or whatever else it is one may be using to publish in. These days, everything this side of multi-megabyte bundles of animated ASCII can have good navigational aids.
And everything should.