I dont have any particular specs. I need to learn it as I am going to be working on clock design in the near future and I do not have much idea of the area
Look throught the app notes on Freescale. Microchip, Atmel, they also have a development boards, so you can start your development wisout waiting for the hardware
The simplest way to produce a clock signal is to use 555 timer. it comes in a small IC package, now it might be primitive but it works. From my experience if you want 5V clock signal, power the chip with 6.5 V ( conformed with Pspice) below i am going to give you couple of websites that will give you an idea.
**broken link removed**
**broken link removed** <- this website also offers a program that will help you chose resistor and capacitor values to control output signal.
**broken link removed** <- another site with prog for download
This i think is the most basic way to create clock signal, you can also use two bjts to make oscillator or you may look for ICs that are more sophisticated. This should help if it is the clock i tihnk you're talking about