The best IDE depends if you are new to programming in general or you if you are new to python. When I installed python to windows 7, IDLE was installed automatically. From wikipedia (https://en.wikipedia.org/wiki/IDLE)
"IDLE is intended to be a simple IDE and suitable for beginners, especially in an educational environment. To that end, it is cross-platform, and avoids feature clutter."
JetBrains PyCharm Educational Edition is another option. It is possible that programs like PyCharm may be a little bit more helpful than IDLE - which is a good program to learn with - regarding identifying syntax errors, etc., if you are learning by yourself.