Op-Amps are great little things. Before you move on, you might want to consider one more step. I like to document what I have learned in a notebook. Looseleaf of course 'cause I'm always learning new stuff. I have some tab dividers and have sections for formuale, different ICs with schematics, transistors, etc. For instance, the 555 section has notes on everything from pin-outs, circuits, astable & monostable operation, a table of capacitor/resistor combinations for accurate pulses, things I learned here, and some circuits.