Many local election authorities provide sample ballots through their websites -- plug in your address and find out which exact offices and candidates will be on the ballot when you vote and also where your polling place is. This year there's a US Senate seat on the ballot in addition to the statewide executive offices, and it's also the first election in Cook County after Board of Commissioner boundaries were re-drawn following the 2010 Census. In that instance, the official who represented you for years may no longer be in the same district as you. For this reason alone, it would be a good idea to find out what districts you live in and who you will be asked to choose between when you go to vote in the partisan primaries next week.
Many local election authorities have website that can tell you where you go to vote. And if you're not yet registered to vote, there is still a tiny window for you to get registered ahead of the primary -- "Grace Period" registration continues into next week, but only at locations designated by local election authorities. Their websites can tell you where to go. If you register during the Grace Period, you might be requried to vote at the same time, so be prepared.
Don't forget, also, that a change in the law allows 17-year-olds to register and vote in the Primary election if they will be 18 years old by the date of the November General (this year, it's on November 4). If you're the parent of a high school student, this may be their first opportunity to participate in our civic life by voting.
If you live in the City of Chicago, the Chicago Board of Elections website is here:
If you live in suburban Cook County, the Cook County Board of Elections website is here:
and if you live in DuPage County, that website is here:
If you live somewhere else in Illinois, the State Board of Elections has a list of all 110 local election authorities in the state, together with their websites (if they have one). Not all offer sample ballots, but many do. Have a look and good luck!
Candidates seeking nomination for judicial seats will also be on the primary ballot. There are almost 200 candidates seeking nomination for over two dozen judicial seats, and that's in Cook County alone. If you want help figuring out who these people are, I recommend the Chicago Bar Alliance, which is a group of bar groups, including the Illinois State Bar Assn, the Chicago Bar Assn, the Chicago Council of Lawyers, and maybe a dozen other lawyers groups that evaluate judicial candidates throughout Cook County. Those evaluations are all available in a simple grid through this website: http://www.voteforjudges.org. For judicial evaluations in the rest of the state, I don't know of any one site that aggregates multiple judicial evaluations, but the Illinois State Bar Association is the most thorough, and their website is on-line at http://www.isba.org/judicialevaluations/
Good luck with your research, and happy voting!