1. The genius with impostor syndrome
This person is both awesome and infuriating at once. You read their book and go, "whoa, this is the best thing ever!" with no exaggeration whatsoever. And the response you receive is usually something along the lines of "oh no, it's terrible... you don't have to be nice." Even after their book lands an agent and sells for a million dollar advance, they'll still go, "oh, I'm just lucky" (okay, so million dollar advances are largely mythological, but you get the picture). It seems no matter how much they achieve, they never quite feel like a "real" writer. And so you waffle between wanting to encourage them and wanting to shake them out of their incurable impostor syndrome.
2. The clueless newbie
This person really, really wants to write a book and has a vague idea for a story but knows nothing about how a book gets written. Their story structure is a mess, their characters flat stereotypes, and their writing atrocious. And oftentimes, they seem to have only a marginal grasp on the English language. As for industry knowledge? All they know is that publishers exist and somehow magically turn a manuscript into a bestseller. This is the person you want to pat on the head and say, "There, there, you'll figure it out eventually." If you're really, really generous, you'll even lead them by the hand to the information to need. But this do so at your own risk, because they might turn out to actually be...
3. The delusional dreamer
This person LOVES their idea for a book and thinks it's pretty much the best thing ever. It's something they've been dreaming up for years and years and is guaranteed to be a bestseller. This person even knows exactly what the cover art will look like and who will play the protagonist in the movie version. Though this person is still in the middle of writing Chapter One, they know that fame and fortune awaits once they slog through the hard part. This person is, unfortunately, the ideal bait for scammers and vanity presses. Though you want to help this person by offering them a reality check, it's often difficult to get their head out of the clouds. And you want to approach this person with caution, because once their bubble bursts, they could turn into...
4. The bitter literary snob
This person hasn't ever read a book they like. All the stuff lining the bookshelves of Barnes & Noble is nothing but fluff and filth. And because there's nothing good out there, they've deigned to write a GOOD book for once. But because those damn greedy publishers only want money, they can't find a home for their masterpiece. They consider themselves to be following in the footsteps of literary greats like Herman Melville who only found fame after death and believe the scholars will someday come to appreciate them, even if the masses won't, because they're ahead of their time. But in the meanwhile, they will talk your ear off about what REAL writers and REAL books are like. And Lord help you if you suggest doing anything to their book to make it more marketable.
5. The salesman who's paying off car loans with book royalties
This person knows how to promote themselves. They're everyone's best friend and know how to make you feel comfortable around them. So you barely even notice that they're always talking about their own book in an effort to get you to subconsciously want to buy it. They'll often tout themselves as a success story and talk about how they're paying the mortgage with their royalties and whatnot, then give you tips on how you can do it too. Though this person is mostly harmless, they can get irritating once you realize that at the end of the day, they're really just bragging and trying to sell something.
6. The writer who doesn't actually read
This baffling sub-species of writer thinks themselves to be a natural-born storyteller with a book to offer the world, but doesn't actually read books themselves. They get their storytelling instincts from movies and video games and news stories, but if you ask them what the last fiction book they read was, chances are they'll mention something they read for English class years and years ago. You can try explaining to this person why it's necessary to read in order to write, since so much about novel writing can't really be taught and is best absorbed through exposure and experience. But chances are they'll tell you that they don't have time to read, and that they don't believe in letting the Establishment interfere with their artistry.
7. The insecure writer who's terrified of having anyone they've met read their book yet wants millions of faceless strangers to read and love it
This person will not let you read their book. You would have to pry the manuscript out of their cold, dead hands because they can't stand the idea of someone actually reading the words they put on paper. Oh, they believe in their story and want to become the next J.K. Rowling like the rest of us, but they want to hide under their bed while their book magically takes off like a Nimbus 2000. If you ask this person what their book is about, they will most likely go on about how they CANNOT talk about it while throwing in little tidbits about the idea (which they secretly think is more brilliant or deep than anything else out there). They showed up to this online forum or local group or whatever because they're hoping someone will spot their genius and take care of getting it out there for them. You're afraid to critique their book honestly because they might actually cry.
8. The happy-go-lucky optimist who wants to give everyone and their book a hug
This person is probably a genuinely nice person, but leaves you scratching your head. They love EVERYTHING. No matter how badly written a work-in-progress is, they'll see the brilliance behind the horrendous grammar. It's hard to tell whether these people are sincerely trying to encourage everyone, if they're just really easily impressed, or if they're hiding nefarious, self-promotional purposes, but they can be nice to have around (because every so often, you need that little gold star comment on your book, even if you're not sure if you actually deserve it). As for their own book? Well, no one wants to give them a brutally honest opinion after all the nice things they've done, and so chances are, this person has no way of gauging the merits of their manuscript.
9. The know-it-all who hasn't published a thing but whose book is totally better than yours
This person is to be avoided if possible. They're closely related to #4 but distinct in that they generally have more experience. They've been to industry conferences and talked to agents and publishers and subscribe to Publishers Weekly. They look down their noses at indie authors and even indie presses because they believe they deserve a million dollar advance and a movie deal. While their knowledge might be impressive, they are often insufferable creatures because no matter how you try to converse with them, they will insist that they are right and TOTALLY BETTER THAN YOU.
10. The tormented artiste
You worry about this person, because they seem to have some deep-seated emotional issues. They write because they must, because the story in their head is just pounding to get out, but it causes them great pain to commit their work to the page. This person will often complain-brag about the agony of being a capital-A Author how it's killing them to write their story, but they go on because they're serving a higher mission of some kind. They may actually turn out to be a genius, but it can be hard to tell.
11. The dogged worker bee
This person wants a writing career, and wants it bad. If they're unpublished, they're out there swapping beta reads with everyone who'll agree to it to make the manuscript the best it can be. They probably also take classes and read character guides and whatnot. And on top of that, they make sure to keep up with the industry by reading the entire New York Times Bestseller list. If they're published, then they're out there pounding the pavement day in and day out in an effort to market their book - giving talks, doing readings, networking at conferences, online networking with bloggers... Listening to them talk can make you dizzy, because it makes you realize just how much you need to do.
12. The old timer who's seen it all
This person has been at the whole writing thing a while and has a pretty clear view of what it's all about. They recognize their own shortcomings and fix what they can while shrugging and muttering "c'est la vie" at the others. They're writing for the sake of writing, knowing all too well that it might all be for just a handful of sales and a gold star. They can be a fount of knowledge, but steer clear of debates because they're too experienced to fall for the whole argument thing. Yet they do enjoy informing others, so ask and you shall receive.