Re: 90 degree angle handrail cuts
It's pretty simple to use a compound miter saw for this kind of a cut. First, set your saw at 45 degrees to the back fence (1/2 of 90 degrees). Then set the tilt equal to the angle of the rail. So if the rail is 30 degrees off of horizontal, set the tilt to 30 degrees off of vertical (60 off horizontal).
But stair railings are typically more complicated than that because of the profile of the railing, and I've never built any. Usually what I've seen done is to bring the railing down a flight and bring the very end of the railing out flat to the corner, make the corner on the flat (simple miter), then angle down the next flight. Or, come down a flight, miter downward to a twist (this requires a carved vertical piece), then miter the bottom of the twist to the rail on the next flight.
You might just do three sections of railing with a gap between each section.
Hopefully someone with more experience than me can give you some instruction.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.