What do you want to learn? Simple hardware things (NE555 stuff with some Linear regulators) or programming (like Arduino / microcontrollers) with some hardware attached?
I ask this because the Tron Club monthly (ish) kits are pretty cool. The beginner kits are more introductions to hardware with the NE555 / linear regulators and some LEDs / some extra things. The advanced kits are programming with an ATtiny.
The cool thing about the kits is they provide you with all of the parts needed for that month's kit and also an online booklet that gives some background/understanding of what is going on. I'm doing a review... thing of the advanced kits on this forum now.
While they wouldn't be "useful" as in getting things to use later. It might be nice to give you ideas/understanding of where to start on your own designs by giving a working example (with the parts!)