My advice to you:
Share a hobby, but have separate hobbies as well.
Laugh together often.
Straighten out the finances, and designate one person to handle the money.
Honesty is the best policy.
It's going to be tough, especially in the beginning.
If you have never lived together, it will blow your mind. Be prepared to compromise. You don't have to do it happily, but don't be a dick about it.
If you have to point out a flaw or something she needs to work on, do it tactfully. During that "honeymoon phase" you are going to be all lovey-dovey, and anything construed or interpreted as even remotely insulting to her will make her cry, pissed or both.
Try your best not to go to sleep pissed at each other. Fight all night and make up if you need to. Working in the morning? That is what coffee and energy drinks are for.
I'm sure I have more advice somewhere, but you will figure out the good stuff soon enough. Good luck, and I wish you happiness!