Does anyone know a good, reputable website where I could find information out about the Church’s rules, etc. concerning marriage?
Depends upon what you mean by “the rules.” Canon law is the place to find the universal law of the Church regarding the Sacrament of Marriage. Canon law specifies impediments to a valid marriage and requirements for a valid marriage in the case of two Catholics or a Catholic and a non-Catholic.
However, Canon Law does not specify every detail. That is left to the pastoral discretion of the Bishop. So, for example, canon 1136 says;
Can. 1063 Pastors of souls are obliged to take care that their ecclesiastical community offers the Christian faithful the assistance by which the matrimonial state is preserved in a Christian spirit and advances in perfection. This assistance must be offered especially by:
1/ preaching, catechesis adapted to minors, youth, and adults, and even the use of instruments of social communication, by which the Christian faithful are instructed about the meaning of Christian marriage and about the function of Christian spouses and parents;
2/
personal preparation to enter marriage, which disposes the spouses to the holiness and duties of their new state;
3/ **a fruitful liturgical celebration of marriage **which is to show that the spouses signify and share in the mystery of the unity and fruitful love between Christ and the Church;
4/** help offered to those who are married**, so that faithfully preserving and protecting the conjugal covenant, they daily come to lead holier and fuller lives in their family.
Nowhere in canon law does it state what the preparation is to be, what a “fruitful liturgical celebration” is, or what help is to be available for the already married.
These details are for the Bishop and his priests to decide upon and implement. Therefore, marriage preparation varies considerably from diocese to diocese and even from parish to parish within a diocese. Some have diocesan-created retreats, some use Engaged Encounter, some use a sponsor couple program, some just have meetings with a deacon or priest. Some require NFP classes, some don’t. Some require 6 months, some require 12. Some require couples to take the FOCCUS assessment, some don’t. That’s all legitimate variation.
Regarding litugry, that’s usually specific to the priest marrying the couple. Some allow strapless wedding gowns, some don’t. Some have very strict rules regarding music (which they all should be in line with GIRM requirements, but some aren’t), or the parish has rules about times of weddings, flower placements, photography, what readings or options are available etc. All legitimate variations within the guidelines of canon law.
So, again, it depends upon what you mean by ‘the rules.’