Digital BW, The Print

Please forgive my post if these are silly questions to most folks on 
this list. I've come to feel like you guys are the rocket scientists 
of the printing business and am unworthy of standing in your 
collective shadows. Now that I've established that I'm a sycophant ...

1. When opening a RAW file from my Nikon D2x, for the best final 
print quality on my Epson 2400, what should my DPI setting be in 
Adobe Camera Raw? I _think_ that the D2x native resolution is 240 DPI 
but I'm not certain. Should I just open at that resolution and then 
resize in PS2 at the end of my workflow before printing? Or should I 
open it at another resolution. I've read that the native DPI of the 
Epson 2400 is 720 DPI, but have also read some folks saying as long 
as it is a multiple of 720 (e.g. 360) that will work fine as well 
(and you can't tell the difference).

2. If my original image size has a setting of 300 DPI (because I've 
already worked with the file and done all my retouching before I 
accessed your collective knowledge), at what stage should I upsize 
the image to a higher resolution (e.g. 360 dpi? 720 dpi?). Should I 
do that as the very first step before retouching? Or the very last 
step before applying unsharp mask?

Thanks for any insight you can provide!

Rob Greer
http://www.robgreer.com/