Photoshop resizing & printing

2 questions;

First, I have some pixel art I want to resize to a much larger (printable) size in photoshop, but photoshop likes to automatically blur sharp edges... is there a way to turn that off so I can resize the pixel art and retain the sharp, pixelated look?

Second, I want to print this like poster size. I plan on going to kinkos or something to print it. What do I need to know about setting up the file? Ex: what's a good resolution (I hear 300 dpi), do I need to make the file CMYK instead of RGB? What format is best for printing and getting it to look as close as possible to the way it does on screen? Any other tips? Thanks.

>>2
This converts the entire image? And will that affect anything else I do other than resizing?

>>3
Thanks, I remember seeing this once before and that was basically what I was looking for... just kind of forgot where the option was lol. And yeah, definitely going to keep it scaled properly.

>>4
The thing is I need a full resolution background behind the pixel art, so I still need the higher dpi for that.

Thanks for the replies so far. Can anyone add anything in about the printing process? Especially about colors- I hate how the colors never look the way they did on screen (which makes sense since screen colors are addative and printing are subtractive, but I know there have to be some tips for getting the colors to look right. :) Thanks again.