Christmas = the birth of Christ
Easter = His resurrection from the dead. http://grigaitis.net/mass/guide/
Here are some relevant quotes from the website above
The first thing you'll see people doing is dipping their finger in some water and then crossing themselves. This water has been blessed by a priest or deacon, and is called "holy water." When people bless themselves with holy water, they are remembering their baptism.
Before everyone takes their seats, you'll usually see them bow, dip their knees a bit, and some even bounce a knee off the floor. This is one gesture that many Catholics do without knowing why they're doing it or how to do it properly. What they're doing (or should be doing) is called "genuflecting." The correct way to do it is by touching your right knee to the floor. You genuflect because the Real Presence of Christ is present in the tabernacle, and genuflecting is an act of adoration to His Real Presence.
The basic idea is that you bow to the altar, and genuflect to the tabernacle. The tabernacle is a locked box where the Body of Christ is kept for adoration and in reserve to give to the sick that can't attend Mass. Most newer or renovated churches have the tabernacle off to the side or in another room, and you can usually find it by looking for a red light that looks important. In older churches, the tabernacle is right in front of everything. If the tabernacle is in front of you, genuflect to it, otherwise, just bow to the altar.
Remember, whenever you're walking around the church and you pass in front of the tabernacle, genuflect to it. As well, whenever you pass in front of the altar, bow to it.
Re the 'crackers', I know you are asking a genuine question but 'crackers' can often be taken as a deliberate insult, mainly because it is a term used by a prominent anti-Catholic. A better term to use would be hosts or wafers.
Catholics believe what Jesus said at the last supper. We believe that when He held up the bread and said 'this is My Body', it really became His Body, and when He held up the wine and said 'this is My Blood' it really became His Blood. He then asked the apostles, and therefore their successors (who are the bishops and priests of today) to 'do this in memory of Me', and that is exactly what is happening at Mass. We believe that when the priest says Jesus' words, the bread and wine, while they remain in the appearance of bread and wine, actually become the body and blood of Jesus. So when people were going up to the priest they were receiving what we call Holy Communion, which is the bread that has become Jesus body. At some Catholic Churches the congregation are able to receive both the host and from the cup. Sometimes the blood(in the form of wine) runs out, which is probably what happened at the Mass you attended. The people who were approaching the priest and not receiving communion were probably either not Catholic or not in a state to receive, they probably had their arms crossed across their chest and would have, instead received a blessing from the priest.
In order to receive communion your children must first be baptised and have made their first reconciliation and their first communion. When/if they do that you will need to speak to the priest about their celiacs, their are special hosts that are extremely low in wheat, or they can receive just a tiny bit of a normal host, or if they cannot have wheat at all they can just receive from the cup. This is what my uncle who was a severe celiac used to do.
I stalked you a little before I answered this post and I understand that your children attend St Benedict's. you are soon lucky, it is a wonderful parish and the order that is in charge of that parish are beautiful priests. My brother and sil live just down the rd from it. I'd have to ask her, but I'm sure my sil would be happy to catch up for coffee with you if you have any other questions.
This post has been edited by Shell14: 17/11/2012, 03:29 PM