When deciding what home school books to use and subjects to teach, I believe you should start with the basics and move on from there. The 3 R's have been around for a long time and still are the basis for any school around. Decide on Reading, Writing, and Math first. When those are set and you're comfortable with those, then more on to adding Science and History and then the electives. This will make the whole process seem a lot less stressful.
When you know what you want to use and teach for Reading, Writing and Math, then you can move on to Science, History, Art, Music, Bible, Health and the rest. Feel free to use my free homeschool planner to help you along the way.
I hope these links to different home school books are helpful to you. Although every homeschool will look different, we all need resources to use to help us along the way. Some families will spend a lot for their resources and some families will spend a little.Those families that spend less do not necessarily have a lower quality of education. Students can learn just as much with free and inexpensive resources as they can with the most expensive video curriculum.
I suggest that if you have multiple ages, that you combine subjects with different children. For instance, if one child is studying World History, don't have another child studying American History and another child studying Ancient History. All students can study the same period of history because if you rotate time periods each year, they will eventually get them all. The same can work for all the science subjects too. There is no reason for different members of the same family have to study different aspects of science at the same time unless the students are doing their work independently and don't need much interaction with mom. I suggest that Science, History, Music, Art, PE, Health, and Bible be set up so that each member of the family is study the same type of material. The older children will be studying more in-depth, but it is a huge help to mom to have everyone learning the same basic aspects of each subject.
It's important that each family pray about their curriculum or resource choices first before they purchase anything.