You'd expect to see menorahs in the windows of Jewish homes.
Potato pancakes, jelly donuts, Hanukkah-themed decorations, dreidels, and appropriate songs.
They would be memories of the holiday of Hanukkah.
Happy Hanukkah Chanukah samei'ach
Hanukkah begins on 25 Kislev. For the year 2013, Hanukkah begins on November 27, 2013 and ends on December 5, 2013. Hanukkah is celebrated by the Jewish communities.
Jewish people
With family or friends, in the home. Some synagogues also hold parties during Hanukkah.
Hanukkah is a holiday. Not a language. During Hanukkah you would say "hello" the same as on a regular day. You can also greet people by saying "Happy Hanukkah".
Anything you would give a one year old for a birthday would also be acceptable for Hanukkah. There are no rules about Hanukkah presents. The only traditional gift during Hanukkah is the gelt (coins) given to children, from about the age of three.
Yes, there is dancing sometimes at Hanukkah parties and dances.
There is no tradition of sending flowers on Hanukkah. That would be like sending flowers on Labor Day.
You shouldn't. Hanukkah and Christmas are no necessarily on the same day, so it would be inappropriate to wish someone a happy Hanukkah on December 25, if that day isn't during of Hanukkah. A better idea would be to look on a calendar to see when Hanukkah falls, then then wish your Jewish friends a Happy Hanukkah on Hanukkah.
חנוכה שמחSee also: More about Hanukkah