As to this kindle edition: it's reasonably well-formatted on the k2, but still has a few typos; the spacing is generally clear. There wasn't a clickable table of contents -- like a lot of other free Kindle books, this is pure text only -- but since this is really more a single short story than it is a book (1065 kindle "locations"), that's not a major fault, and the price makes up for it.
As to the story itself: I doubt there's an english-speaking child who doesn't have at least some familiarity with some version of it; I think every saturday morning cartoon series ever did some version, and every other sitcom. This is the original novella that inspired all those adaptations.
That's the biggest hurdle when reading this: it may be hard for some readers to get past having heard some version or other of Tiny Tim shouting out "God Bless Us, Every One" in five hundred different ways every year of their lives, and some readers might find parts of the story hackneyed in the same way that other Christmas classics have become overplayed (anyone who's worked in a mall during the Christmas seasons will know what I'm talking about).
Despite that, though, this is still a classic story, and readers who can get themselves past that hurdle will be richly rewarded. There's a powerfully archetypal story here, and one that still managed to tug at even my cynical heartstrings, even as overexposed as I've been to endless re-adaptations; I suspect it will do the same for most other readers as well, as long as they're willing to let it.
Even if you don't feel like getting into the Christmas Spirit, though, it's a great introduction to reading Dickens -- probably his shortest major work, and illustrates several of his major themes (urban poverty, workhouses, the Poor Laws, the inadequacy of contemporary aid to the poor, and, generally speaking, man's inhumanity to man). The language is fairly accessible even to a modern reader (Dickens frequently gave public readings of it).
Perhaps most interesting is how much influence this single story has had on our entire modern conception of the Christmas holiday -- it's this one tale that in many ways created, idealized, and shaped the modern notion of Christmas, almost singlehandedly transforming Christmas from the celebration of a sacred holiday to the celebration of a family feast. In the century or two prior to this, the holiday had primarily been seen as a twelve-day rural celebration by a whole village or manorial community -- a celebration that had largely fallen on hard times, due both to Cromwell's Puritan abolishment of Christmas celebrations during the 1640's and 50's and (more crushingly) the increasing urbanization and industrialization of British life, which made such celebrations impractical or impossible. This single story took what had been a dying tradition and revitalized it for the industrial era, refocusing it on the (relatively) secular themes of charity, love, friendship, and the nuclear family -- the same ideas, essentially, that are commonly held at the heart of our Christmas holidays today -- and showing urban families a way to celebrate the holiday and make it meaningful. In a very real way, this story saved Christmas.
So, if you haven't already read it, do so. It's the original -- often imitated, never duplicated. It might tug your heartstrings, and there's something to learn, too, both about the history of the Christmas holiday and its modern meaning.
If you decide after this that you want to read more Dickens, he wrote a number of other "Christmas Tales" -- "The Cricket on the Hearth" and a few others. For the most part they're skippable, not up to the archetypal heights Dickens struck with _Carol_. Instead, I'd recommend David Copperfield; it was Dickens' favorite of his own books, probably the best of his longer works, and it both compares well with "Carol" and strikes on many of the same themes (charity, social injustice, cruelty).