Hi All, Complete Newbie Here

I am 27/m 5'10" 179 lbs. I am not looking to get ripped, and am currently on the nutrisystem diet. Yeah I know, I might get some flak for that but hey at least im trying.
I had some questions, I currently walk a mile and do some reps of stairs, but I am wanting to get more into toning myself, flattening and toning my midsection mainly, my arms and chest have always been kinda naturally toned, legs are okay too. Although I would like to work on them just a little too.
Do any of you have any suggestions on a good workout regimine to achieve these goals? I thought I would ask some people that go through instead of scanning the internet and being offered to "buy this buy that" magic cures. I would rather sweat it out than buy it out.

Well you cant 'tone' one part of your body more than another. The look you're going for is caused by having a low BF%. And you cant spot reduce. You'll have to lose fat from all over your body. The stomache area is a problem for a lot of people, as much as it sucks to hear, its usually the last little bit of fat that comes off, it hangs on for dear life around your midsection.
Even though you cant spot reduce adding a weight regimine to what you already do would be a great way to speed your metabolism, as the more muscle you have the faster it is. And its best to hit your entire body.
By working your legs you will release natural growth hormone which is good. 

Honestly for someone starting off I would go with a full body routine. Its a good way to learn the basics and build a good foundation. Starting strength by Ripptoe always gets great reviews, I've never read it so I cant say. I do however like the general idea.
 
Read this for a routine. 

as far as diet goes, I know you weren't looking for diet help and honestly I've never looked twice at NS but my gut tells me its not ideal. here's a pretty good guide for food.

Hope this helped.

Gin Rummy: Simply because you don't have evidence that something does exist does not mean you have evidence of something that doesn't exist.(from the boondocks)