Hi, and no worries about being new to the old testament.
Here is a nice pocket guide that may help to introduce you to the culture.
http://www.padfield.com/acrobat/history/gods_of_egypt.pdf
Many historians, although disputed place the Exodus around the time shortly after the Hyskos. It really was a troublesome time for Egypt monarchy and I won't bore you with it. But it was this period that greatly brought Egypt's pantheon under monarchy via the God Amon-Re.
http://www.touregypt.net/featurestories/amun-re.htm
In the middle of the 16th Dynasty, with the expulsion of the Hyksos rulers of Egypt, Amun's growth was accelerated due to the vindication of both Egyptian power and Amun-Re as a protector of both the Egyptian state and the Monarchy.
Furthermore:
Amun-Re was associated with the Egyptian monarchy, and theoretically, rather than threatening the pharaoh's power, the throne was supported by Amun-Re. The ancient theology made Amun-Re the physical father of the king. Hence, the Pharaoh and Amun-Re enjoyed a symbiotic relationship, with the king deriving power from Amun-Re. In return, the king supported the temples and the worship of Amun. In theory, Amun-Re could even take the form of the king in order to impregnate the chief royal wife with the successor to the throne (first documented during the reign of Hatshepsut during the New Kingdom). Furthermore, according to official state theology during the New Kingdom, Egypt was actually ruled by Amun-Re through the pharaohs, with the god revealing his will through oracles.
I have a book called Ancient Near Eastern Texts by Pritchard that has many of the ancient Egyptian writings, and I can attest that Pharoah believed himself as a divine god over the pantheon, even as much as being Amun-Re incarnate.
The battle with the Hyskos explains the biblical texts that states: Exodus 1:8 Now there arose a new king over Egypt, who knew not Joseph. The issue with the Hyskos also explains Pharaoh's fear of the Hebrews in the following verses that shows he was fearful of the Hebrews becoming stronger and revolting.. much like the Hyskos.
I don't want to trail off that too much, but we see clearly who Pharaoh believed himself to be, and how others viewed him. As head of the pantheon, we now see a little clearer how each plague was targeted at a different Egyptian God. Amon-Re was considered giver of life and death and held sway over the afterlife as well. With this in mind, we can now see why the Biblical texts says, "and against all the gods of Egypt I will execute judgment: I am the LORD." (Exodus 12:12b)
Clearly, the texts states that God is executing judgment upon all the god's of Egypt, and Pharaoh believes himself to be a god. Simply put, it's judgment time.
But what did Pharaoh do? Why was his heart hardened? Read and you will find that his heart was already hard. Read, and you will find his offence.
Exodus 1:14-16 and they made their lives bitter with hard service, in mortar and in brick, and in all manner of service in the field, all their service, wherein they made them serve with rigor. And the king of Egypt spake to the Hebrew midwives, of whom the name of the one was Shiphrah, and the name of the other Puah: and he said, When ye do the office of a midwife to the Hebrew women, and see them upon the birth-stool; if it be a son, then ye shall kill him; but if it be a daughter, then she shall live.
So we see here that the Pharaoh was killing innocent babies... Why? Because he was fearful of loosing his empire. This is how empires work, and Egypt was the first Empire. When Rome was the Empire in the days of Jesus, we see Herod also killing babies for the same purpose. He was afraid of loosing his little empire.
Let's stop here and let you digest this much first. Ask some questions and well move forward.