When you said "I do" to your promises you created a covenant until one of you dies.  Breaking the covenant has spiritual as well as legal consequences. Don't wander!

Rules I've used:

• Be kind. I know this may seem obvious, but it must be the foremost of all the rules.
• Listen to her problems and trials. She wants you to listen first. Sometimes that is all she wants you to do. We are hard-wired to fix things. It will be VERY hard the first few times to not just jump in and fix things (or at least try to). After she winds down, ALWAYS ask if she would like help. Many times, she will be looking only for a listener. But sometimes she would just like you to be willing to help but not actually to fix it.
• Praise her for things she bought or wears.  Lets her know you think she is a good chooser. This works for everybody, not just your wife. And it's fun!
• Praise her for looking good.  This takes effort on her part.  Shows you think she is desirable and that you appreciate her taking the time to look good for you.  This is ONLY for your better half. Other women will think you are hitting on them.
• Praise her for looking good undraped. This takes a lot of discipline and effort on her part. Makes her feel desirable.  Well, she is!
• Encourage her to do things she said she would like to do as long as they are not actively dangerous. Some of them will work out. Some won't. Praise her when she succeeds and commiserate with her when she fails. Before helping, ASK if she would like some help. IF she would like help, help her just enough. Don't try to solve everything, just help with her stumbling block unless she asks for more.
• When something bad happens (like breaking the glass stove top) ask what she did so you don't do it yourself. Don't yell. "Sh*t happens". She probably feels bad enough about it already. She will appreciate your not yelling (and probably be surprised).
• Tell other folks she is wonderful!  She is you know.  This will make you realize even more how wonderful she is.  The word will get round to her eventually and will make her feel appreciated.
• I heard an explaination on how women perceive they are loved.  "Women have a bucket that contains how much they are loved.  It leaks.  So you have to keep it filled up."  Tell her 'I Love You' at least every day. Put everything you are into it. NEVER say those words casually! Saying it casually makes the bucket leak faster. Every so often give her a gentle bear hug. Put all your gentleness, caring, protection, loving, your desire for her and everything else good you can think of into that hug. Belive me she will absorb all of it. Great for the bucket. And awesome for both of you! Talked to my sister. She said all women are insecure. She recommended I change the every other day to daily and more sometimes. "Make it so."
• When she is pregnant, "I love you" daily. Rub her back. It will alleviate her pain and make her feel cared for. I remember my wife said at one point that she was as big as a house. Told her right back that she practically glowed. She did! Bear hugs are good but will be difficult later in the pregnancy. Gently help her get up. Bring her things she wants so she doesn't have to get up. Thank her for taking such good care of OUR little one.
• Labor. Be with her up to point where the nurses prep her for labor. Then be with her during the labor if the medical folks will let you. We were blessed to be allowed to use the LaMaze method. I was able to be with her and coach her breathing to ease the pain and hasten the labor. Kept her from feeling abandoned. Be with her afterwards to celebrate and commiserate with her. Very glad I'm a man.
• Medical procedures. Be with her during the prep. Try to provide her with a positive, confident attitude before she is wheeled off for the procedure. If the medical folks will allow it, be there for when she wakes up. Help get her dressed afterwards. You will have seen all of her so she won't be embarased by having someone else do it. Helps her feel cared for. Besides she is your lady. Taking care of her will make you feel good too.
• Change her bandages with a cheerful demeaner. No "how gross". She may not be able to reach them. You may need to trim her toe nails. Same issue. She will feel cared for. I got to bandage her up when I first met her in the school office when we were 16. First non-family woman I got to touch. Patched her up for the rest of her life. Was a privelege.
• For your love making, gentleness is the cornerstone. Especially when you are getting started, encourage a sense of humor. "Well that sure didn't work... :-)". Make her pleasure your priority. Men are more easily satisfied. Women have their emotions integrated with their thinking. Not better or worse than men, just different. Because of this she may have difficulties you will not understand. It may be a bit frustrating for both of you, but if you just accept it and reasure her she will be eased. It will likely work next time.
• Just a recomendation: swap off who's on top. You may learn wants she never mentioned.
• Stay in shape. Be her eye-candy.

• Eventually, your covenant will end. 'Till death do us part' will be triggered when one of you dies. It is a true injury. This will likely be the most painful thing that will ever happen to you. You will be horribly sad, but have a week or so where you can think followed by three or four weeks of fog where you can't remember what you did five minutes ago. Find support as soon as you can think again. Sooner than you think you can stand. Don't wait until you think you need it or are "ready" for it. You need it now!
• The last thing you can do for her mourn is to mourn for her instead of her mourning for you. And pray for her soul of course.
• YOU CANNOT REALLY PREPARE FOR THIS.

• Make some good memories that will be easy for both of you to remember. Go somewhere. One place at a time. Do everything there to set it in your long-term memory. Watch each other do things. Take pictures and selfies with recognizable parts of the place in the background. Easier nowadays with digital instead of film. DON'T LOSE THEM! Back them up! If your cell phone or computer dies, you can never get them back unless you back them up. Back up your cell phone pictures to your computer, then back up your computer. How I do it.
• Buy something that you would find only there that are unique to that place. Memory triggers. But not clutter. Clutter dilutes the memories. We ended up buying magnets for each location and put them on the refrigerator.
• Identify movies/tv shows/music she really liked that you can stand watching/listening to again like Halmark movies (daily life fairy tales). She even liked some of the cheesy disaster movies! Yay!
• Learn to cook at least basic stuff. Over time, expand your repertoire. You will eat a lot of it. So make it good. Gives her a little break too.
• Make sure you know how to do the laundry. You will be doing a lot of that too. If you refuse to iron, make sure you can live with the wrinkles (works for me!).
• If she handles paying the bills, make sure you know how she is doing it. Note: I was lucky I did this.
• Find out how she does the taxes.