Despite its enormous qualities, I do not advise reading a neophyte of the cycle, but only to someone who has already made contact with the world of culture through another of his novels (the album is largely independent of each others, we can almost read them in the order you want -except perhaps Direction of the Wind, the Virtual Hell or Hydrogen Sonata for which you better have previously read respectively One form of war, The use of weapons and Excession-). For several reasons: First, its construction which alternates chapters in the normal chronological order, and chapters in a reverse chronological order in which zakalwe gradually remembers her past, is somewhat puzzling. Note in passing that Banks has used the same technique in another SF novel (but not related to Culture), Transition. Then, this novel is very, very black, and his anti-hero and his tone / style extremely dark, disillusioned, may not appeal to everyone. And especially since they contrast with the joviality man of most later books of Culture, Excession in mind. Finally, even if we learn more about the culture in a form of war, for example, it is clear that this is not necessarily the ideal novel of initiation to discover this universe. At this level, the Man of the Games seems more suited to me.
That said, even if the construction of the novel is complex, although his tone is very dark, this is not weakness for romance, quite the contrary. The purpose is very clear (once you understand the normal alternating chapters / flashback chapters backwards), and especially it allows to gradually discover the complex personality of zakalwe, and what led him to become the anti-hero he is in this novel. Certainly, there is a puzzle effect (although less pronounced than in Transition), but it helps to bring revelations and paint the picture of this very complex and fascinating character bit by bit, through a kind of merciless countdown , down two huge final revelations.
In short, a complex novel (but interesting and exciting) in its structure, so dark that it is not to put in any hands (but in fact, again very interesting and contrasting with other books of the cycle , considerably more light), not ideal for an introduction to the cycle, but one of the masterpieces of the cycle. Personally, I place it in the top 3. Ideal also for the anti-hero of amateurs.