The origin of Easter involves the birth of Semiramis' illegitimate son, Tammuz. Somehow, Semiramis convinced the people that Tammuz was actually Nimrod reborn. Since people had been looking for the promised savior since the beginning of mankind (see Genesis 3:15), they were persuaded by Semiramis to believe that Tammuz was that savior, even that he had been supernaturally conceived. Before long, in addition to worshipping Tammuz (or Nimrod reborn), the people also worshipped Semiramis herself as the goddess of fertility. In other cultures, she has been called Ishtar, Ashtur and yes, Easter. This history is what has confused many in the extemely eggagerated and fallacious documentary Zeitgeist. Some forms of Mary worship and adoration are believe to stem through the Semirramis worship of the babylonian time.
It can be confusing as Christians to discern what holidays we as followers are permitted to participate in. On the one side of the spectrum, we can become overwrought with every tradition and public celebration that happens. On the other hand, we can become lukewarm and fall into an idol lifestyle with associating to every pagan tradition and ritual that comes our way. I believe that we must not become too extreme on either end, we must exercise discipline and educate ourselves to understand what is really going on behind these holidays and rituals. Likewise I think that it is acceptable to celebrate these holidays, as long as we educate our children on the reason why we as Christians are celebrating on these days and to shift more focus on the reason for the holiday verses the materialism and commercialization of the holidays and celebrations. Furthermore it is allowable under the circumstance in which we are not engaging in any pagan sacrifices, calling or invoking the names of any other spirit but the Lord of God and or dressing up or engaging in anything that is inherently evil, violent or demonic in nature. If we adhere to these I believe that we as Christians can make our stand and help shine the light of Christ and allow other unbelievers recognize that there is something more meaningful to life than just eating easter egg chocolates or exchanging gifts at christmas time.
You can also watch a more in depth look into the history of Easter and Pagan rituals from the Land of Israel