Where I work, it is expected to exchange gifts between certain people.
I am so thankful that when I took this job (7 years ago) someone took me aside and explained the "culture" of all this. There are 11 people to whom I am expected to give a $5-10 gift. They give me gifts in return. I completely hate this, as I have never gotten anything really interesting or useful (so that's 77 gifts sent off to Goodwill now), and I hate having to spend $50-100 on gifts that I know are likely received with about as much enthusiasm as I have for what I get, and it's a total PITA picking out something that will work for everyone - men, women, young, old that is...well, cheap.
I've given Christmas socks, mugs with hot cocoa mix, fleece blankets, Christmas kitchen towels, candles, tote bags, and now I am OUT of ideas! I wish we would stop this, but every time it's suggested, it's met with cries of horror, that we wouldn't have any "Christmas spirit."

Seriously? I love buying gifts for my family, but buying a bunch of junk for people I hardly know (and in a couple of cases, hardly LIKE - lol) is not my idea of Christmas spirit. But otherwise my job is good (and yes, I'm thankful to HAVE a job!) so I just go along to keep the peace.
OP, is there anyone at your workplace that you trust, that you can ask about what the norm in the office is? Does everyone give a small gift to the boss, or do you chip in for something big? Are there others you are "expected" to have a gift for? What does everyone else usually do?