I liked this book, though I had read The Infernal Devices (its prequel) before, so I felt City of Bones wasn't what I was expecting. It was a good book, but not as good as TID series, which is great, because it means Clare's writing got better and her Shadowhunter world evolved.
Speaking of the Shadowhunter world, there were a few discontinuities with TID, most of which I could get past considering City of Bones was the very first book and she had not finished consolidating its universe yet. However, there was one thing that really pissed me off: women fighting as shadowhunters as something quite recent. Besides my personal feelings about the topic and my personal opinion that it wasn't remotely necessary to make the Clave so blatantly sexist in this era, this fact is totally inconsistent with TID's
Victorian Clave. I mean, I'm glad the writer decided to change such a flaw, and I don't think I would have loved said series if women had not fought equally alongside men, but discontinuities still bother me.
Magnus Bane was probably my favorite character from TID, so I was excited to see him again. I liked most of the characters in City of bones, though I didn't find any of them particularly interesting. Nevertheless, I'm almost sure there's development coming in the following books.
I'm not that fond of Alec, but I totally ship him with Magnus because of reasons.
The plot was ok, but not amazing. I seemed obvious to me since the beginning that Clary was Valentine's daughter, but I hadn't guessed Jace was her brother until he was kidnapped. It was an interesting plot twist. I'm not sure if I'd be so excited about the next books if I had not already read TID. Those three books really captured me into the Shadowhunter universe, so I want to read everything!