Please also read previous blog posts on this topic, especially this one: Grandparent Visitation Rights in Oregon
There are lots of free legal forms online and in print, but none of them will be the exact forms you need in your specific case. You can lose a lot of time and money if you file the wrong forms.
Courts are very, very careful when it comes to child custody legal matters. Oregon courts do not have official or fill-in-the-blank child custody legal forms for parents, grandparents, or for any third party seeking child custody. You need to draft your own forms specific to your legal situation.