A.J.
The process I took when my oldest was around three was starting to research how much material my child would ideally learn in a great curriculum in a great school starting in kindergarten. I looked into international customs as well as regular guides like "What your Kindergartner Should Know" type books. I decided I wanted a "Classical Education" and looked into what would be offered in that. Some people feel more they would like and "unschooling" approach, less structure, more play based, some like Montessori style schools, some focus on religion, etc. So first figure out what kind of education you WANT for your child.
THEN I studied our local public school, and our local Christian private school, met with faculty, asked what would be covered in kindergarten, and to be honest, they weren't going to cover close to half of the material I felt my daughter should have. At age four, she was already proficient at what they were going to teach all year in kindergarten, and the full time schedule wouldn't leave time for her music and language lessons without being "overkill" for a five year old. If there was an awesome charter school, or even highly rated public one, I may have sent her and kept up with supplementing some information. So. I knew that for the style of education I wanted her to have, she would not get it from a school near us. I had to make the hard choice-to emphasize socializing in a school, or learning enough information, because I couldn't have both.
We're now half way through her first homeschool year (kindergarten). We're using the Well Train Mind Guide to Classical Education as the base. It took me a few months to study the book and get prepared accumulating resources before we started. I am astonished how much she is learning in just a couple hours in the morning leaving ample time for her lessons and lots of free play time. I know it's the best option for now. That said, it's a LOT of VERY HARD work on my part, and I am hoping to move to a better district in the next couple of years and send her to school.
So. Figure out what you want (style of education). Figure out what that would entail by studying curriculums in that style. Figure out what you have (in your available schools). And then figure out the best way to get the education you want. Maybe your school is great or sufficient. Maybe you would need to supplement. Maybe you would choose to homeschool. Good work starting to think about it now, it does take time to figure it out!