I actually decided to do something I've never done this election. I'm going to be a poll worker... not to be confused with a pole worker. Luckily this is Canaduh so I don't need to pack heat, unlike in Murica.
Deputy Returning Officer or Poll Clerk?
The first could give you laryngitis by the end of the night, and the second could give you writer's cramp (if your voting station happens to be one of the busy ones).
Don't let the scrutineers boss you around. They usually try to whittle out more information than they're actually entitled to.
Bring lunch, supper, and snacks, make sure you have coffee, tea, juice, or whatever, and something to read during the downtime. I once made the mistake of going to vote on the way home (provincial election; I've only worked municipal and federal)
after I'd picked up a pizza for my supper, and since I was on foot there was nowhere I could leave it before going in. I never saw 10 people perk up so fast, and of course I had to tell them they couldn't have any.
Also bring your sense of humor. The election itself is a grim thing, but there are times when a sense of humor at the polling station helps. We needed this in the election of '93 when EC shorted us on supplies (only half the name tags we needed, among other things). It was lucky that I happened to bring a roll of masking tape with me to get the cat hair off my clothes; I hadn't had time to do that at home, so I just tossed the tape into my bag of stuff. We ended up using some of it so the workers could tear off strips of tape, write their names and positions on them, and stick them to their shirts.
Finally... have fun!

It's a long day, some of it's insanely busy, some is very quiet, but you'll meet new people and have an interesting experience. And of course it's extra money in your pocket.