Jesus spent his boyhood years in Nazareth before beginning his ministry when he was about 30. After moving his home to Capernaum, Jesus returned to teach in the synagogue of Nazareth twice more, but was rejected both times. One time, the townspeople were so outraged at Jesus that they tried to throw him off a cliff to his death. What could he have been teaching that was so enraging? We have an idea the more you get to know Jesus through the scriptures... He was very bold in bringing the message he did, but many believed him because of the acts he performed. He had proof he wasn't just making things up, but had stamp of God with him.
Now, we find a Byzantine church that was built over the place where it is believed that the angel Gabriel announced the birth of Jesus to the virgin Mary. In 1966 the Roman Catholic Church began constructing a new basilica over these remains and today this church is the largest church building in the Middle East. The Greek Orthodox Church nearby is built over the town's water source. We see churches and different things built over older ruins in much of that region in the world. We saw some places like that in Greece also just this last summer when I went there. In different places, newer buildings, sometimes whole towns are built on top of others. We know this happened in Italy too in some places, etc.
As far as ancient sources go, we know little about Nazareth. For now, its limited to the New Testament which is a great ancient source, but there is some dispute over this of course. I have not seen good reasons to disregard it as an ancient source, just because it seems to conflict with what many would like to believe about history. Nazareth is mentioned in the Byzantine period, 4th Century A.D. Archaeological excavations have confirmed that the city was only a small agricultural village during the Hellenistic and Roman periods.
Nazareth was a relatively isolated village in the time of Jesus, with a population of less than two hundred. Its location was inside a "bowl" atop the Nazareth ridge north of the Jezreel valley. Now, the location of upper Nazareth is home to thousands of Jewish residents. Over 60,000 Israeli Arabs live in Nazareth area today.
I found it interesting that Nazareth is also known as En Nasira, Japhia, Mash-had, en-Nasirah, Nazerat, Nazareth of Galilee, Nazareth in Galilee, Yafti en Nasra. This will help in the researching of Nazareth. So keep that in mind as you are learning and reading more.