Quote: "What things do you think would interest you the most?"
I believe that people can find loads of useful material about game engine basics i.e. resource management, timing, states and more (which differs for various programming languages). At the moment I feel that we need something to cover trivial techniques (some of which have been discussed in this thread): decals, lights & shadows, sound culling, render optimizations, etc. Once again there is wealth of information available but most of the time it is way too complicated to be implemented using DBP native commands. I suggest you to take a look at some of the Game Engine Gems and Game Programming Gems series books. They cover range of essential subjects where each technique is explained in about 2-5 pages including code snippets and illustrations. You don't have to be a writer to do this. Nor you need to explain the technique it self (yet again tons of papers available for all this). Essentially I would imagine you focusing on DBP/GDK aspect i.e. how to use current TGC command set to achieve certain effects. For example I use GDK+PureBasic but the commands are still the same so by stressing them rather than the programming language specifics would be advantageous.
Quote: "I guess what you'd like to see is it all in one place, with some clear explanations, rather than having to search around, scrutinizing code and examples and trying to piece it together from old threads. I know that's the sort of thing I'd find useful."
Exactly. Additionally, most of the time people suggest really useful methods, but 99% of them are quite self contained and when implemented in a regular game engine environment don't live up the expectations. For example if you search blob shadows rarely you would find explanations on how to do decal clipping or make decal follow the surface to which it is applied. These are just some of the issues I've faced with while doing technical write up for my FPS engine.
Phew, thats a long one.

Intel Core2Duo 2.2GHZ, 2GB, GeForce 8600M GT 1280MB, Windows Vista Ultimate SP2, PureBasic 4.61 + DarkGDK 2.0