Some of us need help.

It's bad enough that we are magnetically attracted to bookshops, unable to pass one by without ducking inside, but when a novel comes along with a title like this, the urge to pick it up is also irresistible. Deborah Meyler - who, it is safe to assume, is also a bookshop addict - has been wise enough to signal upfront the selling point of her debut novel, namely the ramshackle second-hand bookstore in Manhattan where her English heroine takes a job and finds order and comfort in her otherwise chaotic life.

The Owl is so appealing - dust, dirt and down-and-outs notwithstanding - it is tailor-made for stage or musical. Tiny, cramped, staffed by eccentrics (as are many of its customers), it sits like a sore thumb in one of the world's most commercial neighbourhoods. For Esme Garland - the name a nod to two icons of page and screen - it is paradise, a "glowing little jewel of a shop".

A few days into her new job, she enthuses: "I love it most in the rain, I think, in the night rain when it rains and rains and rains like this, and Broadway glistens, and the Zabar's sign glows, and the wet street reflects all the headlights and the traffic lights and there is the canary yellow of the cabs against the black, and people running by, a short bust of speed to get somewhere sparkling and warm again. On these winter nights we are still open until midnight, so a Monday night in the rain in January, like this, this is a good night. When it rains here it's torrential, drenching and incessant, and I want to dance outside in it and turn my face up into it."

That sentimental, lush, youthful paean to the city and the shop - indeed to life itself - captures the tone of the novel. In terms of plot, though, The Bookstore is decidedly thin. A post-graduate studying art history at Columbia University, Esme falls in love with Mitchell van Leuven, a handsome, blue-blooded academic who, when he learns she has fallen pregnant, first encourages her to have an abortion and, when she refuses, drops her like the latest Dan Brown.

It is at this point, staring at a bleak future as a single mother with no income but a scholarship, that Esme takes a part-time job in the bookshop. Here the story picks up. Meyler conjures a menagerie of unconventional types, from the bookstore's gentle, health-freak owner and his sullen sidekick Luke, to the tramps who sell them grotty books and occasionally steal their more expensive stock.

Were the novel and its plot never to stray beyond the bounds of the shop, The Bookstore would sing. As it is, the schlocky will-she/won't-he story that unfolds as Esme's lover plays fast and loose, faintly demeans the intelligence at work in other aspects of this work. Meyler may realise this too, for only in the person of the repellant boyfriend does her tender touch with character falter.

A pantomime baddie, who can say, "I don't want you working in that drab little secondhand store when you meet my mother", van Leuven is a mere prop, leaving one in no doubt where the novel is headed. For some, perhaps, that will not be a problem, so sparky and engaging is Meyler's heroine and so likeable the cast she introduces. The bigger issue for this reader, though, is that emotional momentum is lost, long before the tale's end.

Meyler has chosen to write in the continuous present, a risky tactic because, while it creates a sense of immediacy, of diary-writing freshness, it can also lead to the kind of longueurs that afflict poor diarists, with linking passages about domestic or humdrum affairs that are dull yet unavoidable if the narrative illusion is to be maintained.

Yet, overlong and uneven as it is, The Bookstore has real charm. Esme's unusual blend of innocence, grit and sexual frankness is memorable, lifting her above the ruck of predictable romantic leads. Someone once described Kate Mosse's novels as chick-lit with A-levels. On that level, Meyler deserves a 2:1.