May I suggest that rather than worrying about civics test you spend some time before the interview working on your English? Apart from the civics, you also have to pass the English test during the naturalization interview, and your posts here (particularly the "Now worries" thing) indicate that you may have a problem in that department.
As for the civics test, it really is rather a joke, and a typical 9-year old should be able to pass it after 30 minutes of study. Most questions (such as "What does the Constitution do?" or "What does the Congress do"?) are common sense questions that require no study at all. Just about any common sense answer, no matter how phrased, will be counted as correct by the IO, provided that the answer is delivered coherently. The worst thing you can do with such questions is to try to study for them textologically, that is by memorizing the specific wording of the answers. Use common sense instead. There are a few questions that do require memorization (such as the number of amendments to the Constitution, the number of members in the U.S. House of Representatives, a couple of questions dealing with specific dates, etc), but the rest of them are completely trivial.