how high should my desk be? I have a adjustable desk (standing/sitting desk with motor and saved settings). I keep adjusting this one and keep trying to find out what are the best settings
how high should my chair be? Coincides with number 1 as I would think they relate to one another.
Your chair needs to be low enough that the front edge doesn't restrict circulation to your lower legs. At 6'3 it might not be something you've run into. It should be high enough that your thighs are taking a portion of your weight, not just your hipbones.
With the chair taken care of, then you can do your desk.
Old-school "keyboard operator" stuff recommended the keyboard be practically in your lap, your upper arms straight down, and your forearms at 90 degrees. Newer standards are a bit different, but they all assume you're not doing anything other than typing. Certainly not using the desk as, well, a desk. I usually have my keyboard pushed up against the monitors, at arm's length, to get room for papers, reference material, and the trackball, which sits in front of the space bar. You'll have to make your own compromise.
I switched back from a modern USB ANSI keyboard to an IBM Model F a while back. One problem with that is that, with the desk at an appropriate height for non-keyboard work, the F is enough thicker that it's not as comfortable to type on as it should be. I've never had much luck with wrist rests, but the Good Idea Fairy has suggested making something like a thick mat to put in front of the keyboard, effectively making it lower while myforearms are on the desk. I'll have to remove the spacers under the desk legs to get the same operating height, though.