Custom 404 Error Page

I am working on eCommerce website & want to create custom 404 error page. So, how can I create best custom 404 error page for eCommerce website? If I will create custom 404 error page so, will it effect on my SEO ranking or not?

 

Google for it, lot's of stuff to read about that

 

create a notfound.htm file if your host support it.

 

If your using Cpanel you should be able to do it from there, here is a quick video on how to do this I hope it's helpful to you.

http://www.youtube.com/watch?v=LrQE-IqDXMY