If you weren't already aware let me be the first to tell you: in your marriage you need a clear plan and vision. Some couples that I've spoken with are experiencing real relationships problems due to lack of a clear plan up front. You know the old saying, "If you fail to plan, you can plan to fail".
When you enter into a relationship with your future spouse you're coming from two different backgrounds, two different life histories and two totally different points of view. Before your heart takes you away you need to sit down and have a discussion to make sure the plans that you both have are the same or at least similar.
Below are a few conversations that I think are essential to have prior to getting married:
1. Children - Do you plan on having any? How many do you want? If one person already has kids are they willing to have more? Seems simple enough but I've seen people not address this then get into a relationship and be ready to leave because their spouse doesn't want any or any more additional kids. Also don't think that they'll change their mind later. When it comes to a topic like children you need to assume that what they say will be their final decision and deal with the situation from that point of view.
2. Finances - You need to know in detail about each other's money and spending habits. Is their credit score severely low because they've been out of work due to the recession or because Louis Vuitton keeps calling them? Sometimes people are afraid to bring up this conversation or may think that the topic is taboo but it should definitely not be off limits. Especially if you're seriously considering marriage and spending your lives together. After the initial conversation you can also go further to discuss who will pay the bills, will you operate a joint account and what are the expectations towards spending (i.e. do I need your permission before I buy these Christian Louboutin shoes)?
3. Religion - Can you come into agreement on religion? Do you want someone that worships like you? What if you're both Christians but your spouse thinks that he can worship at home just like you worship at church? Do you require that they hold the same beliefs? If you hold two different belief systems how will you raise your kids? Again don't think that you'll automatically be able to change someone on this or that they'll come around later once you get married.
4. Goals - Do your goals match up or even make sense? Sit down together and write down one-year, three-year and five-year goals for your family. When finished, compare and discuss. This will tell you a lot about where you each think your future family should go.
There are other conversations that are definitely important but this is a good starting point. Get to know your potential spouse before you say, "I Do". Understand what they think and why they think that way. Most importantly don't be afraid to have the tough talks. Having them now will save you heartache later.