We've been getting this question a lot lately. Our search into Orthodoxy began on the down low (do people even say that anymore?) mainly because we had no idea where it would lead us. As we learned more and more, we became more open with those that were close to us and willing to hear us process everything. However, to those who's first encounter with Orthodoxy was when we told them we were catechumens in the Orthodox Church, it has been a bit confusing. I wish that there was one easy to way to explain the differences. But the main thing I want to communicate to people are the similarities. Our view of God is still the same. Everything that we are learning in our catechumen classes is what we already believed. Sure, there a some huge differences, but I would almost call them additions, rather than differences.
Trying to explain what an Orthodox worship service is like is quite difficult as well. Like many things, it's in the experience rather than the explanation. I can tell you what incense is and what is does, but until you smell it, until you leave a service with the sweet scent on your skin, you won't understand. I can tell you what an icon is and it's purpose, but until you see one and venerate (kiss) it, you won't truly know.
Frederica Matthewes-Green wrote an essay entitled "12 Things I Wish I'd Known..." (http://www.frederica.com/12-things/ ) It's to help prepare first-timers for an Orthodox service. There are many things that are explained that I feel are helpful for someone coming into the liturgy for the first time. My brother gave it to my husband and I before our first service. We gave it to my mother before her first service. Now, we are showing it to you.
While you are there you should read other articles of hers. She was one of the many influential writers that helped us find our way home.
