Choosing Paint

So I've realized that I know pretty much nothing about paint.  I feel okay with acrylic craft paint, but when it comes to painting real things like walls or furniture I'm lost.

I've been doing a lot of searching about paint this week.  We have our final walk-through of our house next week and I want to bring some paint swatches and ideas so I can see what will look good once all the insides are complete.

I've always looked forward to painting, but when it comes down to it I have lots of questions. 

How do you know what the colors will look like on the wall?  

How do choose colors that flow throughout the house, and which finish do you use?  
Anyone else with me?


I'm hoping so, because I'm going to share a few resources on paint that I found this week. 

COLOR

Love this one! You can upload your pictures to try different colors - Sherwin Williams Paint Vizualizer

(Is this what you used for your door Sizzle?)

Choosing colors that go together - True Value Paint Idea Cards 
and Sherwin-Williams Color Themes

FINISH

Choosing Paint Finish - About.com


All Things Paint - Thrifty Decor Chick - This one is a great over-all resource to check out!


Hopefully this will help some of you as well in any paint projects in the future. 
Do you have a favorite paint resource or any opinions or insight into paint?  Please share!