The easiest place to find palladium is catalytic converters. The recovery and refining of platinum group metals is not a simple mater however. Since you are new here I do not know your level of expertise.
If you are new to refining precious metals I would suggest you start with card edges/fingers using AP (HCl with H2O2) to recover gold. This will allow you to learn the basics of taking precious metals into solution and precipitating them as well as the problems with the ever present copper.
If for some reason as a new member you have a high content palladium scrap, tell us what it is, and you will get guidance.
Oz is right , cats are a good source , there's also Palladium in good quality white gold jewellery ,in the UK it can run at 15 percent down to about 5 percent , I gather some e scrap has a Palladium content but don't know which parts.
In escrap you can find Pd in some relays, pins, and monolithic capacitors. Mind you not all of these items contain Pd, but some do you'll have to test to identify the ones that do.
I know for a fact the monolithic capactiors on Intel slotted cpu cards contain Pd.
Thank you for all the help guys I think that I will takes oz's advise and start out on something a little simpler since I am very new to this. Again thank you very much guys.