El was the supreme god in Canaanite religion. The Canaanite (Ugaritic) religion borrowed heavily from its more powerful neighbors, so El may derive from a number of Sumerian or Akkadian gods. El was also know as El-Elyon, meaning God Most High, and later El Shaddai, meaning god of the mountain. El supposedly lived on Mount Saphon, hence the "El Shaddai," name. He was a member of the Ugaritic pantheon and was later equated with Yahweh in Exodus 6 v2-3. One of El's sons, Ba'al Hadad, slays a sea monster, Lotan or Lawtan, according to Ugaritic texts. This is very similar to Yaweh's fight with Levithian in Isaiah 27.
El is also used to refer to a foreign god in several other places.
The plural Elohim is a very curious considering the use of the singular El. I've been unable to find any other examples of a majestic plural in ancient hebrew, but that certainly doesn't mean they don't exist. If anyone knows anything else about this term I'd certainly be interested in where it may come from and what or who it originally refered to.
The most interesting bit of info I found regarding the term Elohim comes from Moses Maimonides in his Yad ha-Chazakah. Here Elohim is considered to be a class of angel, and not even a very high class of angel. This bit of info came from wikipedia though, so I'm not sure if its entirely accurate.
Here are a couple other websites that have useful information on this subject:
Encyclopedia Mythica
Jewish Encyclopedia
