Here is a great link for hand rails.
But if you do use this link in your handrail build, please please! do a similar writeup like the one in the link for
the WOA in small projects (I am sure Jay would help with the pictures and links) . Also Here are 3 additional tips
1.) If you use hanger bolts you can build it without plugs (install them into the handrail while the new handrails are in place, from below) you will need a helper (or a rope) to bend it as you drill and screw in the hanger bolts in to the rail from inside the cabin. Starting at one end working toward the other.
2.) a saber saw (can be called a jigsaw) works as well as the band saw
3.) 6/4 is the perfect size for the hand (on Mine I used some additional routing to make them look like the Pros make for $$$$$)
for this project you need a drill & hole saw (can be a hand drill), table saw, router & bits, and a saber saw and some teak: now for the link.
An Alberg link on how to make handrails
Best of luck:
Norm