What do i type in after the @ to email someone in the netherlands?

i thought it was @ home.nl

.nl ... but u have to know his mail provider

It can be @home.nl, but it can also be @zonnet.nl, @hetnet.nl @quicknet.nl or @yahoo.com.
Or one of many others.
Each internet provider also provides an e-mail address, besides many people use an address connected to their website if they have one, use a free service like Yahoo or Hotmail or use one of the e-mail providers that are particular to the Dutch market, like Moerstaal.nl, which has a long list of funny and personal addresses, like Genius Am I, but that in Dutch.
So unless you know what kind of address and which provider, just try.
If you are in doubt, and the mail is sensitive in nature, send a test mail first, and ask your friend to reply on it, so you are sure it came to the right address.

nl

That depends on the person's provider. Many Dutch people simply use hotmail.com or gmail.com. Others use Dutch providers such as hetnet.nl or zonnet.nl or even home.nl