1. Be sure you love Him
It shouldn't be an infatuation, it shouldn't be for a pregnancy, it shoulcn't be for conveniance, it shouldn't be for fun or out of boredom. be sure you really love him.
2. Be sure he loves You
Look at No.1.
3. Be sure you know his Parents
Know what they're like, if you get a long or if you don't get along...and weigh how much this is going to affect your life together - and if it even matters.
4. Be sure he knows your parents
Same as for No.3.
5. Be sure you agreed on a prenup
And if you find the thought offensive - you should discuss this prior.
6. Be sure you agreed on how to finance your household
7. Be sure you divided your chores and responsibilities 50/50
If you both work, and in today's economy it's unimaginable that a person does not work, then chores should be done 50/50. Choose the ones you don't mind doing and make sure you both agree on the divide.
8. Be sure you agree on the idea of offspring
Do not talk about it when the marriage has already been officiated - do it waaay before that. This point is a huge deal for many people. Some feel strongly for and some strongly against having children. Make sure you know where you stand. And don't count on your partner to 'change their mind' after a while.
9. Be sure you know where you're going to live