The primary source for the events that took place in the time of Chanuka is Sefer haMakabim (Maccabees I) (English Translation). This book was originally written in Hebrew by a religious Jewish soldier. It's quite fascinating, and I recommend that you read it. (Unfortunately, the original Hebrew has been lost.)
Here are all the relevant verses for the above-mentioned stories:
- Eliezer Maccabee being crushed by an elephant.
6:43-46 And Eleazar saw that one of the elephants was equipped with royal armor. It was taller than all the others, and he supposed that the king was upon it. So he gave his life to save his people and to win for himself an everlasting name. He courageously ran into the midst of the phalanx to reach it; he killed men right and left, and they parted before him on both sides. He got under the elephant, stabbed it from beneath, and killed it; but it fell to the ground upon him and he died.
- The rebellion staring in Mode'in when the greeks tried to make the jews offer a sacrifice
2:23-27 When he had finished speaking these words, a Jew came forward in the sight of all to offer sacrifice upon the altar in Modein, according to the king's command. When Mattathias saw it, be burned with zeal and his heart was stirred. He gave vent to righteous anger; he ran and killed him upon the altar. At the same time he killed the king's officer who was forcing them to sacrifice, and he tore down the altar. Thus he burned with zeal for the law, as Phinehas did against Zimri the son of Salu. Then Mattathias cried out in the city with a loud voice, saying: "Let every one who is zealous for the law and supports the covenant come out with me!"
- The Greeks outlawing commandments such as Rosh Chodesh, Milah, and Shabbat.
1:41-49 Then the king wrote to his whole kingdom that all should be one people, and that each should give up his customs. All the Gentiles accepted the command of the king. Many even from Israel gladly adopted his religion; they sacrificed to idols and profaned the sabbath. And the king sent letters by messengers to Jerusalem and the cities of Judah; he directed them to follow customs strange to the land, to forbid burnt offerings and sacrifices and drink offerings in the sanctuary, to profane sabbaths and feasts,
 to defile the sanctuary and the priests, to build altars and sacred precincts and shrines for idols, to sacrifice swine and unclean animals, and to leave their sons uncircumcised. They were to make themselves abominable by everything unclean and profane,
so that they should forget the law and change all the ordinances.
- Yehudis killing the Greek general, Helifornos
This story actually has it's own book, The Book of Judith (English Translation, Chabad Summary).
Chapter 13: So Judith was left alone in the tent , with Holofernes stretched out on his bed, for he was overcome with wine... She went up to the post at the end of the bed, above Holofernes' head, and took down his sword that hung there. She came close to his bed and took hold of the hair of his head, and said, "Give me strength this day, O Lord God of Israel!" And she struck his neck twice with all her might, and severed it from his body.
- the children hiding their learning by playing with tops.
As you may already know, playing dreidel is a fairly modern custom that is based on a popular secular European game. According to Seforim blog, the earliest source for this "story" is Otzar Kol Minhagi Yeshurin, published in 1890. However, R' Josh Waxman believes that the earliest source is Avodat Eved, published in 1877. (Other explanations for why there is a custom to play dreidel can be found here and here and in the Bnei Yissochor 2:25.)