For anyone using T98-Next, there's a translated version
here (via
zophar.net). Plays pretty well, with no funny text. To load Touhou disk images (.hdi files) into it, go to Main > DISK > HD DRIVE and under drive 1 click the text box just to the left of the Edit button. Browse to the disk image file and click the big power button to start. Since they're disk images, all of your high scores and whatnot are saved into the images, no external score or config files like on the Windows games.
I'm not sure what system requirements the PC98 Touhou games need (FPU, CPU speed, RAM, etc.), but I have the CPU set to i486DX, CPU clock at 66MHz, and Memory at 64MB.
To configure your graphics settings, go to Device Manager, select GDC.nhw and click Settings. You can set your frame skipping, screen resolutions, screenshot folder, and toggle fullscreen and windowed mode.
One recommendation, under GDC.nhw, set your frameskip to 1, as AUTO can sometimes cause the emulator to chug.
As for basic emulator controls, there's 6 big buttons on the left side of the emulator window; (from top down) Power switch, Sleep/Resume switch (I think it only works for PC98 Windows), Reset switch, Toggle hardware settings, Help, and Quit.
Outside of that, most of the default settings T98-Next comes with should be optimal.
For Linux users: This works great under Wine. I've had occasional problems with it starting emulation with the emulator window not displaying, but I've recently reinstalled my system (cleaned up Wine folder, etc.) and it hasn't cropped up again.