Please indulge me if you will:
First of all thank you for posting an honest question! It is rare on here, so I will try to give you as complete of an answer as I can.
1. You offer web-sites because you cannot explain it all in a post here, very true, I am sure. It is the same with us that Believe in God, Basically, I cannot believe that we created ourselves, so there has to be a higher power. But to get into the nuts and bolts, you would have to study the New Testament and the Catechsim of the Catholic Church. I reference the Catechism not only because I am a Catholic Convert, but also because it is the most complete Christian reference in print that you can turn to to get an Idea of the beliefs of all Catholics and most Protestants.
Personally, I am 42 years old, have been a Christian, a non-Christian, and now a Catholic Christian, this has taken a lot of use of logic and reason, along with searching for the truth in a lot of different faiths and in having no faith as well.
Thanks for not calling us all delusional, or stupid, and I will respect your beliefs as well.
My suggestion, if they are Catholic, go to RCIA classes, they cover the basics over a period of 6 months or so about an hour a week. That will give you the bare essentials so that you can understand where they are coming from, but not nearly the fullness of the faith.
As a logical person, if you are trying to come to a conclusion on two different points, do you research BOTH sides equily? Does research on one side only give you a sound, answer? How much time have you spent reading the New Testament? You may be trapped by a pre concieved Belief that there can be no thruth in Chrisitaniaty and they may be being supported by a continued consumption of arguments from the non Christians ONLY!
So, I am going to suggest a couple of sites for you:
www.Catholic.com
www.Catholic.org.
peace be with you !