Are there any sites that will tell me which yu gi oh cards people are looking to buy/trade for?

I have cleaned out about 4,000 yu gi oh cards. I was asked to put some for sale/trade for pokemon or webkinz cards. However, I have NO idea which cards people like or are good. Is there a site that gives information about this and that would provide an accurate and fair price as a basis? Has any other parents tried to do this; and was it worth it?

Are there any sites that will tell me which yu gi oh cards people are looking to buy/trade for?
if your really looking to get rid of them then email me and tell be all cards that have a shiny pic, shiny pic+gold letters, shiny pic+silver letters. Then ill tell u the commons/rares im looking for.