The preview images link to a vendor (Amazon, Ebay, or head to your local hardware store) to purchase the items. I also added two circuit building introduction activities.
Electricity Kit Items (2-3 students per kit)
Two C-Cell battery holder (1) with snap connectors
C-Cell batteries (2) - D batteries and D cell holders would also work great.
Nine Volt Snap Connectors (1) I prefer hard shell but soft is fine
Alligator wire clips (6ish per group) Don't buy the cheapest available as a wire failing is challenging for students to troubleshoot! The cheap ones just crimp the alligator clip to the wire.
Aluminum Foil (Optional) - You can use aluminum foil in a pinch to replace the Alligator wire clips.
2-Volt E10 base bulbs (3) - I'm really specific as some just don't last due to the glass breaking easily. Avoid LEDs ones as well. My goto is the #222 Bulb rated at 2.25V, 0.56W with an E10 base. Image above should link to this one. This bulb handles drops and extra/under voltage very well.
E10 base bulb holders (3) - These make it easy to attach the alligator clips to each bulb.
Christmas Lights (Optional) - If you want to a very inexpensive option try cutting up a set of incandescent Christmas lights. They work pretty well and save you the cost of the bulbs and bulb holders. The only downside can be they have more variation in brightness than the #222 bulbs above.
Single Pole Light Switch (3) - Super robust and cheap. The students like learning how to connect them to circuits and they save your batteries.
Multimeter - (1) Ideal 61-340 for about $80 is good or something cheap for about $10 works surprisingly well. You can also do tons of conceptual activities based on the brightness of bulbs without a multimeter.
Amazon List link: http://a.co/cNCcwd5