In terms of public schools, not all school districts are created equal. Some kids learn much better in safe environments in consolidated suburban schools rather than in urban or rural settings. States that spend more money on education see fewer dropouts than states without a tax base. You get what you pay for, especially in education spending.
Spending absolutely has an effect on education. Think about the difference between an impoverished, inner-city school and one that is well-funded by taxpayers in a rich suburb. One school will be seriously lacking in the technology and other resources needed to help things to run smoothly. Provided that there is a responsible person at the reins, investing in our children's futures is a wise move.
Education results are impacted by spending, but educational attainment is a function of more than just spending. Educational results depend on myriad things in addition to funding, like the students at-home situation. Does the child live in a two-parent home, and the educational attainment of the parents (did the child's parent graduate from high school). More funding is better than less, but it's not a simple relationship.
Everyone seems to think it takes a ton of resources to teach children when really all it takes is time and energy. Kids can learn from every day life that happens around them, they do not need expensive calculators and fancy notebooks in order to become smarter individuals. If anything, all the expensive educational tools distract from the actual learning process.