Kristy,
I started HSing my DD last year for K. I didn't have a clue about what to get, so I had her do a bunch of BrainQuest books, etc. I found a program called K12 that seemed to be good (had all the subject, electives, etc) but cost about $5,000 per kid/yr for everything. BUT many public school systems throughout the country use their stuff for HSers and it is FREE since it is through the public school system. so, instead of paying $5,000 a kid, we get all of our books and misc learning materials (blocks, beads, scale, paint, clay, map, blow up globes, counters, individual books for Lang Arts, etc) free. It is the best thing we could have hoped for.
My DD is enrolled in the public school system, without going to public school (which means permanent records and transcripts when she needs them,) we have an 'education specialist' that lives close and calls bi-weekly to go over how DD is doing, any questions we have, etc., and she can move through the courses at her own pace. They do test for reading/math when you enroll and place her in a reading/math level based on those tests. My daughters tests placed her in K math at the beginning of the year, but by Oct we already had the 1st grade books and materials. We are now halfway through 1st grade math. We can also continue working through the summer, which we will likely do.
I looked for WI and there is a public school option in your state. It does not matter what district the school is in, as long as you are a resident of that state, you can attend. I would go to K12(dot)com and check it out. It works perfectly for us and I have had to spend $0 on her education this year. They literally give you everything you will need, except the pencils. For example, if you have a K or 1st grader, you will get the Phonics Works program, which comes with two binders full of letter/sound tiles, teachers book, student pages, three white boards, markers and eraser, sight words flash cards and step-readers. They sent us paint, clay and oil pastels for art, scales for science, globes, maps and history-related story books (like The Egyptian Cinderella) for history and a TON of manipulatives for math. We also received 10-15 individual books each for K and 1st Lang Arts, so we don't even have to hunt them own n the library. They also do the Handwriting without Tears, which I have seen other HSers on DIS mention.
Our district also gives each child a laptop computer to use while they are in the program. I don't know if your school would do this or not. It should be mentioned that ALL K12 students use the same materials, no matter if they are going through a public school or paying the full K12 tuition themselves. Your DD won't be using the same books that are used in your state's public schools. Although the books are made by major text book publishers, they are specifically for HSers (as an example, my DDs math book mentions 'your child' in several places, even though it looks like a book they would use in school.)