The first step in managing your finances for God is to dedicate it all to Him. I realize this is much harder to do than what I just wrote.
The first step is realizing you own nothing. "The earth is the Lord's, and everything in it, the world, and all who live in it." (Psalm 24:1). This means your wealth is not actually yours. Instead, you are simply a steward. A steward of your house, car, family, and money. Everything. Take a minute and wrap your head around that one. This is the exact same relationship I have with HP. They gave me a computer to use and take care of. When I'm done at HP, I will give the computer back. Everything I do on the computer should be to help HP. Now image you worked for God and he gave you everything in your life. Are you using all of it for the good of Him? I realize it's a high standard - I'm not even perfect with HP.
Of course, there are some benefits to this situation too. Since I'm just a steward (or manager, whatever), I do not need to be wrapped up in all "my" things, because they're not mine. If I lose or gain something, it shouldn't matter because it wasn't mine to begin with. Hopefully you also understand that, like when borrowing something, it's still your responsibility to take care of it and try not to break or lose it. It's a subtle shift in thinking, but a powerful one.
It was strange waking up this morning because when I looked at Jessi, I realized she's been temporarily entrusted to me. I need to take care of her, but not for my own pleasure, but for God's pleasure. In some ways, that implies a whole lot more responsibility.