People have asked what I use for a HS curriculum. I primarily use Time 4 Learning and supplement it with free or very low cost items.
Time 4 Learning is very inexpensive at $19.95 per month and offers what I think is a very good core curriculum. In our financial position I'm not able to afford a separate curriculum for each subject. I don't have a way to spend $300 on a science unit, another $300 on a math unit and so on. If you do that's great but I have to work with what I can afford! Time 4 Learning is great for kids who like to work online. I've found your child doesn't have to have a long attention span to get through a lesson or chapter. The characters used are interesting and the graphics are neat! Not only is the concept introduced but it's reviewed before your child is quizzed or tested. I enjoy the worksheet feature which allows me to print PDF's to use as review and I love how T4L keeps all our information in one easy to access place. I do wish there were more worksheets for Science and Social Studies. Hopefully they will in the future.
I also love being able to access three grades at a time - the one before the grade you're using and the one after. I helps greatly with planning or being able to see/use additional information from grades prior or later. It's very similar to Compass Learning used in public school with the only difference I can see (having used it while working in PS) is the Odyssey Writer. The T4L version does not allow me to use the instructor fields I was able to use in PS. It's not really a big deal and we've worked around it. I'd have to say I'm extremely satisfied with the product and even if you're not homeschooling it's worth a look at to keep your child from sliding back in the summer.
I supplement with Spelling City (I think I paid $20.00 for the year) for spelling, vocabulary and some great games geared to our spelling lists plus the ability to do everything online including the grade book. I love their handwriting sheets as my daughter wanted to learn cursive handwriting and they don't teach handwriting in public school.
I use some of the worksheets from Everyday Math as this is the curriculum my daughter has used since first grade. I'm also using Spectrum Math worksheets which are pretty much of a review of what she's already learned as we purposely started on it late for that very reason - to review. I found the book at Staples.
For Language Arts along with Time 4 Learning I use Basic Not Boring - Middle Grades L/A book. I use random worksheets which are generally witty and fun to reinforce what is being learned via T4L. I've only used a handful so far because I'd like to stretch the book as long as I can since it's geared toward Middle School. If your child is a genius then you'll think that's silly but I've decided I'm not going to just speed through things so I can brag how my little darling is doing 9th grade L/A but she's only 11. I also do a lot of writing - especially poetry and short stories along with a daily log of current events. Jack also has a blog she updates weekly.
For Social Studies I supplement T4L with a couple of books. One is The Complete Book of World History grades 4-8 by McGraw Hill. I find the book "ok" it really doesn't have much detail but I like how it's laid out in a timeline format. The other is Events That Changed the World by Igloo Publishing. I have enjoyed the book because it goes up to the election of our current president which is pretty cool. Each page is a different achievement or invention that helped change the world. It includes things like the Magna Carta, discovery of Penicillin, the space shuttle Challenger disaster, and hurricane Katrina.
Science is pretty much on T4L but we do use Activity TV (online) to find experiments, Beakman's World on Netflix, and a science fact book I found at the dollar store! Next year our goal is to beef up science by adding more biology and chemistry.
That about covers the typical stuff! We do PE and Health (health is part of our Science curriculum). We do art and music weekly and we also toss in some cooking because cooking is math and chemistry all rolled into one! We also visit a lot of websites like PBS, NOAA, and Grammar Blast. It's amazing the stuff you can find free for homeschoolers!