Gospel does in fact mean "Good News".
There are 11 completely preserved gospels, 5 infancy gospels, and many other partially and reconstructed gospels. There is also mention of other gospels that have not been found... including the Gospel of Perfection and the Gospel of Four Heavenly Realms.
Only four gospels are considered canon by most Christian faiths. Like most religions, Christianity has undergone an evolution of changes in the canon, to extract a fluid faith from the many early texts of the many Christians of the times... The process has been ongoing since the first preserved writings of early Christians, around 200 c.a., when Origen wrote commentary on the Gospel of John.
Christianity has a fascinating history, and if you have a good professor, you will be given the history and a chance to learn some of the faith. I minored in Theology at Notre Dame, and I found the most fascinating aspects of the religion in the devotion of the modern peoples... how something could so obviously be a myth, regarded as true...
It is disputed whether Seneca the Younger actually said, "Religion is regarded by the common people as true, by the wise as false, and by rulers as useful", but the aphorism is still valid, regardless of it's source.
