You face one of the toughest decisions a woman in our society (or I truly believe in any society, ever) has to make. Some woman are working moms, and some are stay at home moms. Everyone believes they are doing what is best for them and their families. My guess is that you, like my DW, feel the pressure to be at home for the kids and to have a successful career.
My DW is also a NYS certified teacher (k-8 and 9-12 English). She stopped working when our first DS was born 13+ years ago. She has been sustitute teching for several years now. We have had several different arrangements through the years. She has been in a few different districts but found that the neighboring district was the most convenient. The elementary school starts 50 minutes after our boys need to be at school. The tougher part is the gap when our boys get home. This has involved friends, family mutual arrangements (one year we knew someone who needed coverage for her daughter before school) and afterschool programs. Starting last year we felt they were mature enough so we started letting the boys key themselves into the house. The benefit of sustituting is being able to arrive just before school and leave as soon as the last student is gone. No plans to write, papers to grade, phone calls to return etc. (you know: all the things that most people don't realize teachers have to do). This means she can be there in the afternoons as well as those days that she is needed around the school as a class mother, etc. She can also turn down work when the boys have a different day off than her school.
Every year now we go through the discussion of whether it's time to go back FT so we can start saving for college (or book a longer trip at a deluxe resort). Be warned though, Substitute teaching is a thankless, underpaid, unappreciated job. There will be days that you are assigned to a rotten class, not left any plans and not given any frees. That being said, It has worked out well for us (easy for me to say) and DW is glad she can contribute to our income. She is usually asked at least once each year if she wants a FT position so its comforting to know that when she wants to go back FT she can. Good Luck.
Oh and BTW, make sure your DH is willing to chip in. I have to admit, I'm not always as helpful as I should be. Getting the kids off to schol, working all day, coming home and getting homework done, driving to practices, getting dinner ready AND trying to keep the house clean is a monumental task that I could never do. I'm sure I don't tell her that often enough and that I don't help enough.
