Comprimise. Communicate.
Been married 14 years, and every time we have ever goten into a fight, it ended up being a little bit my fault, and a little bit her fault. When you get to a problem the first thing you should ask yourself is what you did to contribute to it. The most poisonous thing for any relationship is to think that you are 100% right and your partner is 100% wrong.
Have kids. Best thing in the world.
Wait a few years to have kids, but don't put it off forever. When you do, make sure you have solid life insurance, and figure out who you want to raise your kids incase of your death. Watch those nanny-911/supernanny shows, lots of good advice/techniques there.
Start two Roth IRA's now, and max out your contributions, no matter how much you have to sacrifice. Best to invest at first in a diverse stable of really large companies that offer automatic "dividend reinvestment", such as Coca-Cola. For really long term, go for GE stock.
Read up on retirement planning. You will need $2-$4 million to really retire with a minimum standard of living. (this is future dollars, so it isn't as far-fetched as it might seem)
Try not to have any secrets, and be as honest as possible.
A good long-term relationship is a lot of work and requires maintenance, but is extremely rewarding. I can only hope you are as happy in 14 years as I am.