Eclipse is the third in a series of novels by Meyer. The first two are Twilight and New Moon. There's a fourth book coming out in August called Breaking Dawn. What I really like about these stories is that even though they're about teenage love, vampires, and werewolves, they're appropriate for actual teens to read. No sex and no bad language. It's a real pleasure to read an excellent story that I can pass along to my grandkids.
Eclipse provides some new information about werewolves and vampires. There's plenty of action and some old enemies make their appearance. However this novel is still focused on the love story between Bella and Edward, and Jacob! Highly recommended.