I need to know how to put new corks in home made wine bottles. I have made a lot of home made wine and I don't know how to go about it. I have the wooden corking device, but I am not sure if I have to wet the corks first. I have tried but they seem very difficult to get into the bottles and some of the cork broke off. These are real corks, not used before. I would appreciate any advice. They are also the right sized corks for the bottles.

It sounds like your corking device doesn't work correctly for your purpose.
Check with your local home brewing store to see if they rent floor corkers. These have a multiple jaw compression ring in the center that squishes your cork such that it fits in the neck of your bottle, and then a small push rod on the handle that pushes the compressed cork smoothly and completely into the neck of your bottle without any risk of breaking off.

For example:
http://morewinemaking.com/view_product/6300/102727
http://morewinemaking.com/view_product/19436/102727
http://morewinemaking.com/view_product/6174/102727
Or, by hand, this is the best option:
http://morewinemaking.com/view_product/19435/102727