So this year the kids are doing a couple of different science classes but for the purposes here I'm throwing together their zoology stuff (we also have geology and marine biology).
The first thing I do is go thru their main book they are working out of, in this case it's the Sassafras Twins.
Then I look around the house and see what I already have sitting around that can be added to it as well..
I also have a couple of others of the card games but this one works well with the first few chapters in the book. I look to see what kind of movies, documentaries or other programing we may have playing available on netflix, youtube, and Hulu that might go well with it as well as going thru their fun reading books and adding in whatever might go with which ever chapter we are on. Then I look at things in our area that might go well with it as well, field trips are the funnest part to take a look at. I do try and plan them according to the progression in the book. So for instance the first chapters cover the African grasslands so we might go to the cheap day at the zoo and head straight for the African animal exhibits. When we get to ocean animals (at the end of the book) I already have the 2hour marine boat tour and science class booked. We have tickets for the aquarium purchased already (Thank you Groupon!)! It does sound like a lot of work, but in reality it takes very little time (Other than the field trip planning since I do the field trips for a larger group than just the family, it tends to be the most time consuming).
Yes, I do similar for each subject they want to tackle. History, cultural studies, etc. I will admit it helps that we (my husband and I) are avid readers and have a ton of books at home. The kids also have a nice selection, but that usually takes me a little longer to go thru since I'm not always 100% certain what they have and where.