Need documentation on oscillators

Hello everybody,

Where can I find documentation on how to best create a clock signal

for feeding my CPLD ? I am using an EPM 570 T100A5 CPLD, and I need a

50 Mhz clock for my CPLD.

Application notes, or whatever documentation on the best way to do this,

ie resonator, quartz oscillator, etc would very helpful.

Thanks !!

Eric