Question: Can anyone point me to a tutorial for electronic noobs that 
explains how to use op-amps and what I can do with them, besides
amplification?

Answer: 
Hyperphysics has a pretty good section about opamps: 

* [Operational Amplifier Concepts](http://hyperphysics.phy-astr.gsu.edu/hbase/Electronic/opampcon.html)
* [Op-amp Varieties](http://hyperphysics.phy-astr.gsu.edu/hbase/Electronic/opampvar.html)
The "IC Opamp Cookbook" paperback was ~THE~ standard for hobbyist electronics back in the 80s. Still a good reference.