There are many, many kits advertised for a makerspace area. Although we don’t have our “space” yet, we are moving forward to equip the library with some of these kits to heighten awareness of hands-on STEM teaching. Our initial purchase of LEGO Mindstorms kits have been used twice in classroom wide teaching and in workshops throughout this year.
It’s a great start but there are loads of other kits out there. The Littlebits kits seem to target the younger classes, perhaps grades two to six, teaching foundation concepts of circuits. I think these sets, especially with the Arduino Coding Package, would be a great place to start for an elementary school.
For the more advanced students in middle and high school, I think that an arduino computer with some additions would be a great start. Starter kits are also a great way to go since project instructions and accessories are included. Arduino and Raspberry Pi seem to be competing for the school maker market.