Before you go vote, take a look at your ballot. For any precinct in Minnesota, you can visit http://pollfinder.sos.state.mn.us/
If you are still puzzled by Instant Runoff Voting, here is an excellent video that covers the basics: http://minnesota.publicradio.org/displa
Even if you understand how IRV works in the mayoral race, you may still want to watch this second video, which explains how IRV works in races like Park Board At-Large, where more than one person wins. http://minnesota.publicradio.org/displa
An important note on this is that in the Park Board At-Large race, order matters. There are three open seats, and you can vote for three candidates. But it's actually important to put your favorite candidate first, your second-favorite second, and your third-favorite third. (Or, you might list your long-shot candidate first because s/he is most likely to need the help.) But ORDER COUNTS. Previously in this race, there'd be three open seats and you got to pick three candidates and they each got one vote. Now, you get fractions. Watch the video -- it's complicated. The short version is just, order counts.
It also counts in the Board of Estimate and Taxation race, but I think it's less likely to matter there.
Finally, I liked this post from R.T. Rybak about looking to see who's funded by whom, before casting your vote: http://rtrybak.tumblr.com/day/2013/11/0