honey and sting

Actually, Jews are pretty individualistic LOL. In other words, if you don't follow all the "rules", chances are you won't be the only one. People might be very into the prayer, or more into talking with their neighbor. Some pray out loud and some silently, or not at all, just observing. Some sing, some on key, others not. Some places have beautiful melodies and others just seem to drone. It depends on the type of synagogue, of course (orthodox, conservative, reform, reconstructionist, havurah, etc -- not exactly "denominations" but all variants of Jewish observance)as well as Sephardic vs. Ashkenazic (Eastern vs. European traditions), and individual differences in communities, but in most Jewish services across the board, basically sometimes you sit down, and sometimes you stand up. You can pretty much tell what to do from watching what others do and following along. There are some things you do with a little bow, but no one looks to see if everyone is doing it, and besides, it's really up to the individual. It's perfectly all right to be an observer, and to ask the gabbai (a sort of usher) to let you know what is considered polite as an observer. While this is true mainly of orthodox or some conservative synagogues, it doesn't hurt anywhere for a woman to wear non-revealing clothes, skirts rather than pants, and a top or dress with sleeves. Married women in the more traditional places cover their heads (hat, scarf, etc). Also consider what sort of service you'd like to see. I like Friday night, for welcoming the Sabbath. Saturday morning is more extensive and include reading from the Torah (chanted in Hebrew, with some interesting rituals around the handling of the Torah scroll), and holidays each have flavors of their own. In short, it would be pretty hard to make an idiot of yourself -- there's just too much going on, and too many different ways to do it. :)