To be brutally honest, if you are 're-starting', there wasn't, and still isn't a heck of a lot wrong with the D3100, and if you only ever used it as a big Point & Shoot, on green-box auto (and not a lot wrong with that!), it would still offer a hell of a lot before any short-coming in it's spec started to hamper you!
I have bought two D3100's, both 2nd hand, in the last year, one for my daughter finishing her O-Level & starting her A-Level Photo-courses, other for my O/H feeling left out and after using Daughter's wanting to step up from a bridge to the 'same'. I have a D3200, that's three years old now, and bought 'over' the better value D3100 'new' only because I had aspirations to go fishing.... use a fish-eye lens, which makes 'round' pictures in the middle of the frame, 'wasting' about a third to a half of the pixels; hence the higher pixel count was likely to be useful when I came to manipulate such shots in post-process. However, remarkable degree of 'sophistication' in these 'entry-level' cameras is fantastic, and from my stand-point, the 'extra' packed into the higher level 'enthusiast' DSLR's would pretty much be wasted even on me as a more clued up enthusiast, for a lot of the time, if not most of it!
For a beginner, or a re-starting one, the entry-level models are bang on the money, for money and features, and I really don't see much point recommending paying extra for the next 'upgrade' camera body, you may never find you need or want, and is likely been replaced in the range with something with even more whistles and bells by the time you do need or want one. Of choices, I would suggest the D3300 is the exact gear for the gig, here; while if you chance on a 'deal' over a D3200, you would still be well set, while if you want to put pennies to better use, going second hand a D3200 or even another D3100 would STILL be more than enough to do the job.... and I would put more though and more money into the lens to go with it.....
I find the 'kit' 18-55 on my D3200 more than 'adequate' 90% or more of the time, and tends to be my most used lens, but on the higher pixel count D3200 I do think that the resolution of the camera is starting to show the limits of resolution of the kit lenses, and the higher still resolution of the D3300 is likely to only make that more so. Using 'legacy' lenses from old film cameras on it, has supported the suggestion. Hence for my daughter's academic endevours, I partnered her D3100 with the 35mm f1.8 'prime' that offers the same field of view as a 'nifty-fifty' on an old 35mm film camera, sacrificing zoom and image stabilization for image quality and a faster fastest aperture, for shallow Depth of Field effects and a brighter view-finder. Putting that lens on my camera, (when she'd let go of it long enough!) Again supported suggestion that at that level its the lens that's the weak-link, not the camera body.
STILL, 18-55 is still my most-used lens, and I live quite happily with its 'short-comings' for the convenience it offers and the 'cheapness'... essentially 'free' with the body, where anything else is as much as another camera! With the 55-300 I have a huge range of focal lengths available, but again, the 'kit' level 55-300 is still out-stripped by the camera body and legacy lenses in teh same focal length range. And for what I use most often in that lens, to be perfectly honest, the 55-200 would not be much of a sacrifice and save even more pennies, while for convenience, the 'do-it-all' 18-140, is awfully 'tempting'.
BUT, that is where I would save your deliberations for; picking the lens or lenses that are likely to be most 'useful' for you, NOT worrying over the bamboozeling and increasingly irrelevant differences in 'spec' between more or less expensive camera bodies.
IF you start to expand your use over what you used to, then it's likely that whatever subjects start to interest you will beg more specialist lenses than a 'kit' 18-55 or 18-140, I would suggest as fair enough start point, so save your cash for them, when buying a Siggy 70-300 for birding or getting a Tokina 10-24 for land-scapes or street photography, or a Nikkor 85mm prime for portraits, will be begging big spend, and saving £100 or more on not over-buying a body, could be the difference between getting such a lens or not... and Glass-Lasts! bodies don't! So spend as little as you can get away with on the body, and put cash towards the lenses you want or may want to go with it... or whatever body you buy in the future. Here and now, though, choice of body isn't that big a deal, don't sweat it.
Remember, better photographers take better pictures, not better cameras.... you want to get on the learning curve with something that will help you become a better photographer, you don't 'need' much more than the basics right now to do that, and becoming a better photographer from it, you'll still get better pictures even with just 'the basics' and knowing how to get the best from it, than having a better camera, and not knowing how to get the best from it.
but most importantly learn how to use the camera, there are so many free tutorials online - make use of them 
