The following link an excellent resource for information about the books of the New Testament.
For example, let’s say that you are interested in learning about the evidence for the authorship of John. The link on the book of John covers external evidence that starts with mentioning Irenaeus and other church fathers that affirm its authorship to John the apostle. It also lists internal evidence of two types: concentric proofs and incidental evidence. There is even a section responding to arguments against Johannine authorship.