As any engineer will tell you, 0.1uF ceramic capacitors are the magic fairy dust of electronics - sprinkle them over your circuit schematics for good luck! But seriously, a 0.1uF capacitor right next to the VCC pin of your chips will improve stability by filtering out power supply spikes and noise that can cause flaky behavior. Adafruit love these little guys, they have 0.1" spacing so fit into any perf or breadboard, compact and good quality. Adafruit use these exclusively in all Adafruit's kits, and are always handy for any project or prototype! So useful, they offer them in packs of 10.
Each capacitor is coded 104, 0.1uF value, -20%/+80% tolerance (so they're best used for power supplies, perhaps not great for precision filter design), 50V max voltage.