Evangelical Question

I was raised Catholic but fell away from my faith because I felt that the
Catholics had some whacked ideas, like transubstantiation. Most Catholics don't ask any questions and are Catholic because they were born Catholic. I have always been the one that asks why and wants to know all the reasons for everything and collects as much info as possible. Having faith is difficult for someone that is always looking for tangible facts and incontrovertible evidence. At times I have felt that God definitely exists and at times I have felt there is a chance he doesn't and there is a physical explantation for everything.

Anyway, I have been attending Battlefield Assembly of God with my wife. Last week I felt that God talked to me and told me I would be confused until I was saved. He told me that He understands I will have questions but if I just place my faith in Him He will help me find the answers. I took a leap of faith and have placed all my trust in God and His grace and accepted Him as my Savior. I now feel that I have found a home with the biblical evangicals. This is the first time I have publicly professed this.

This blog seemed like as good a place as any to try to seek some of the answers that I am looking for. If anyone actually reads this and can help I would appreciate a response.

Here's my first question: A Catholic's faith is based on Scripture and tradition. I don't recall where, possibly in Romans, but I have seen the NT epistle passages stressing this. Protestants believe in sola scriptura or that Scripture is all that matters. They also passages to show this. So where did the bible come from? Catholic view can explain this because books were left out or included based on the tradition and guidance of the church itself. Protestants don't believe in this. I also believe that Scripture alone can give you all you need to find salvation but how do Protestants justify what books were included or left out?