heh that was a bit of a rant, but if you google 'digital camera noise' there should be plenty of info on it. it's generally nothing to get too worked up about. noise is simply random signals that get sent into the image either from just random variation and in most cases increase with the temp.
if you do a google image search there are plenty of good examples of noise in a digital image.
a quick search turned this up
noise can be avoided in almost all cases by shooting at the lowest iso (film speed) which of course will make it harder to shoot moving chickens without blur.
a scanner depends on your end use of your photos. you have to make a determination if it's cheaper to pay someone else to scan a few images or buy your own machine because you have a lot of them and want to save money, have the time, and / or want to do it yourself. for casual use finding a scanning service would probably be the best or finding a friend who has a scanner.
when i shoot my 'art' photography i prefer to use film and thus need the scanner. for anything else digital is absolutely the easiest. since digital is more prevalent, i'm guessing that there aren't many low-end or cheap film scanners out there, but even a very good one can be had for about $500. typically the process is pretty simple, put the film/slide in, set some settings and then it puts the file on your computer in a few minutes where you can photoshop (or whatever you have) away.