Step 1
Keep all electronics off! To respect the importance of the ceremony, be sure to turn off all cellphones, beepers, and Blackberries. Don't turn it to vibrate, as you'll be tempted to pick it up and start fiddling with it during the service. If you must be on the look out for a certain call or email, leave it on vibrate, and leave the temple if you wish to answer your phone. During most services, there will be men walking around the aisles to make sure everyone is paying attention to the bar or bat mitzvah's lesson. If you are caught texting, playing a game, emailing, browsing the internet, etc., they will poke you and ask that you please put your electronic away. If you continue to be a disruption, they'll confiscate it and return it at the end of the service.
Step 2
Don't take photos in the temple. Most ceremonies will have a hired videographer as well as a photographer to be documenting the event. If you're very interested in getting some photos or videos, ask them for information.
Step 3
Smoke off the grounds. The temple, the sanctuary, and even the temple grounds are not a place for smoking. If you'd like to smoke, smoke fifty feet or more from the temple as a sign of respect. Otherwise, try to make it through a few hours without a smoke.
Step 4
Sit or stand as needed. At certain points in the ceremony, the rabbi, bar or bat mitzvah may ask for everyone to stand. This is usually to sing a certain song, and show respect. It's not necessary however to stand, so feel free to remain sitting at this time.
Step 5
Dress appropriately. If there is not a dress code on the invitation, (i.e., "cocktail attire"), you can generally get away with these guidelines;
Men- Men should wear a formal suit and tie with dress shoes. You should also cover your head. Don't bother with cologne, and instead take a shower to smell fresh. If you do decide to use cologne, less is more! People are coming to this ceremony to congratulate someone making their entrance to adulthood, not to get lost in your fog of spray-on deodorant. Be courteous of those around you, and skip the perfume. 
Women- Women should wear a dress, or formal pants and a nice top, (i.e., sweater, blouse. However, skirts/dresses should cover the knee and shirts should cover the elbows. Once again, be light on the perfume.
Step 6
Don't talk during the service! For many people, the service is the hardest part of the ceremony to get through. The bar or bat mitzvah will be reciting parts of the Haftarah in Hebrew, so unless you understand Hebrew, you won't know a word they're saying. However, be courteous, and don't talk. If others are singing along with the bar or bat mitzvah, feel free to sing along if you know the words.
Step 7
Save the partying for the party portion. Most bat and bar mitzvahs have parties after the service. This is a less serious time during the day, which usually includes dancing, eating, drinking (alcohol), and receiving bar or bat mitzvah gifts.
Step 8
Check with Jewish friends. If you'd like clarification on a particular question that's been brought up, ask someone who's Jewish nearby, or someone who's been to many bar or bat mitzvahs. They'll probably know the best answer to your question. If you are still shaky on their answer, and would like to clarify, consider searching on the Internet. However, this is not always the best choice. Make sure that if you research a question, you get your answer from a reliable source. An example of a good source is My Jewish Learning.
Step 9
Be respectful. Even if you aren't Jewish, don't understand Hebrew, or aren't religious at all, be respectful of the bar or bat mitzvah, and help to celebrate with them. They've been practising for this day for years, memorising the Haftarah, writing speeches, and coordinating all events of the service. Be courteous, and keep in mind all of the effort put into the event.
Tips
- When saying a word of congratulations to the bar or bat mitzvah, say "mazel tov" (mah-zuhl toev). This is Hebrew for congratulations or good luck.
- Don't turn your back on the Torah. Although this is usually an act that most are ignorant of, it can sometimes be noticed in more traditional services. It is considered disrespectful to turn your back on the Torah.
- Don't clap in the temple. This rule is sometimes broken, depending on where the service takes place. For instance, some services take place at a hotel or country club, where you'll probably clap along with the songs and such. As a simple guideline, don't clap unless other more experienced people are clapping.
- For simple comprehension, here are some words that will be used;
- Adonai - God
- Yisroel - Israel
- Bar'chu Adonai - praise the Lord
- If you don't catch a word, or would like to ask for the meaning of a word, don't ask someone near you. If you'd really like to know, jot down a simple spelling so you can remember the pronunciation, and ask someone after the service.
- There are also prayer shawls that may be offered at the beginning of the service. Most of the time, these are reserved for the Jewish adults coming to the service. However, they may be offering every attender one. Don't feel a need to wear it; you can if you wish, but if you are uncomfortable with wearing it, don't be afraid to decline.
- Feel free to pick up a Kippah. These are often called Yamakas. They are the simple headwear for a service. Most of the time, they are offered to all the males of the service on a table inside the temple. There are usually barrettes nearby to keep it in place. Don't feel a need to wear it, as many people simply decline. Sometimes, there is lace offered for the women of the service. Feel free to pick one up even if you aren't Jewish, as it is used to respect the sacredness of the occasion.
- Ask someone more experienced for clarification on any questions you may have.
- If you don't know what kind of gift to get the bar or bat mitzvah, give them an amount of money. Usually, it's a multiple of eighteen, since this is good luck. Keep all of the charges for the party and service the bar or bat mitzvah family is facing while thinking of a good amount.
Warnings
- Don't turn your back on the Torah in more traditional services. Literally. This is disrespectful.
- Don't talk loudly during the service. If you are considered too much of a disruption, the men overseeing the audience may move you to a more isolated location within the sanctuary so you won't talk.
- Keep all beeping electronics off unless you are waiting for an important message or call.
