Sorry I took so long to reply, got distracted. The links provided give you a good DIY start, BUT without tying it into computer controlled fuel/ignition you're very limited on how useful it will be. It can work as an "idiot light" so to speak but not really useful for tuning.
Also it is very easy to get a false reading with aftermarket valvetrain or sometimes pistons or a very worn engine block.
You may be better off just tuning it the "old fashioned way" with plug reading, vacuum reading, and some common sense starting points.