When I was preparing to be married, I asked a few women for advice. One of them was Karen from the Sower's Corner. Karen kindly sacrificed her time to share her thoughts extensively. She included some great thoughts about marriage to a sinner, which I've copied here. I still haven't read "When Sinners Say "I Do"", but it is on my list of goals for this year!
First, and I think the most important, is knowing that you are both sinners. This dashes unrealistic expectations that we have for one another. It also brings us closer together, realizing that it is all by grace. God's grace is the glue, used by His Holy Spirit Who is developing our character. Conforming us into Christ's image.
With all of that said, there is an excellent book that just came out called "When Sinners Say "I Do" Discovering the power of the Gospel for Marriage by Dave Harvey. I just bought this book and I'm reading through it.
In the beginning of your relationship you tend to read a lot of books on marriage and relationships and then that falls aside...my advice is to invest in your relationship by reading and buying good books on marriage. In every marriage, there are times where because of life's demands you become "dull". You sharpen and stir up your feelings and love by periodically (maybe once a year or every six months) reading or re-reading a good marriage book. I would start with When Sinners Say "I Do".
As you are reading books on your role as a wife, remember that you are a complement to your husband. So all of your strengths are there to complement his weaknesses and vice versa . . .
Another area about roles that I had struggled with and now understand better is when it is appropriate to speak to my husband about something that needs correcting with him. For a long time, I thought that I shouldn't correct him, I should only pray for him and let the Lord do the correcting. This was not a loving thing for my husband. Remember we are both sinners and we both have blind areas. Sometimes these blind areas keep us from really walking in the Lord the way we desire. The Lord often times will show us what is needed and we must gracefully bring correction.