This 16 MHz quarts crystal oscillator will provide a very high speed for your microcontroller and allow you to get a whopping 1 Mbps (one million bits per second) for UART communication., among many other things.
8 MHz and 16 MHz is like a magic number with these 8-bit microcontrollers, their clock speeds and prescalers used against the clock speed.
This oscillator is rated for 20 pF, but remember this is only for the ocillator and does not consider the PCB capacitance, so a capacitor that will work for you in your prototyping stage and do the hard math the find the real capacitor when you are ready for production so the oscillation will be perfect.