Vanguard is your friend. Research to be sure which specific fund or funds work best for your situation, but seriously — auto-save and forget.
Also, as I’ve said before, read regularly the Bonddad blog. They just finished a set of pieces on the four things they are going to keep an eye on this year, and You can track them easily on whatever data tool you fancy. If you’re going to need a place to put your free floating anxiety about money that actually might be beneficial, this is it.