I am recently marriend and wondering how to add my wife to the deed of a home I've owned for 3 years?

I think this stuff is done via the local government courthouse. Call and ask.

You need to file a quit claim deed transferring ownership from you to you and your wife. However, if you have a mortgage you will need to get permission from the mortgage holder to make such a transfer since they have a lien on the property. So I would contact them. They may help you do it.

Often of course there is really no "rush" just be sure to have your will up to date in case something happens, But if your mortgage company does not care about someone being added to the deed, it is simple to hire an attorney or a title company who will do a quit claim deed.

Definitely talk to a title company first so that you do it right the first time. So many times I've run across deeds that are incorrect or missing information.