This is a very good question.
First, if you get into a good college that has many opportunities, you're already done with half the process of trying to find a job. Companies will go to good schools that they want to recruit from. From there, it's more job experience that counts.
However, for a lot of companies, your GPA will matter. For companies such as PwC (PriceWaterhouseCoopers), GPA is pretty important. Consulting/I-Banking internships require a decent GPA (around 3.5) and such. Also, most clubs on school such as consulting clubs require at least a 3.0, but won't recruit anyone unless they have above a 3.7 or know someone really well in the club. Furthermore, for a lot of jobs in the first two years of college, they want to see whether you have taken classes that are applicable to the job; the reason why I say the first two years of college is that they assume you have taken the necessary classes by the third year. That is why most companies do not hire freshmen/sophomore, and instead go for rising juniors, seniors, or just graduated students.
With that said, there are also jobs that DO NOT care that much about GPA. For example, I go to Berkeley, and our engineering classes are some of the toughest in the country. My friend right now is on academic probation with a 2.2. However, he's really good with coding and front-end development on the computers and stuff like that (practical skills necessary for the job). I don't even think his job looked at his GPA; they wanted to see how good he was on the job. He now interns at IGN, which is the biggest video game reviewer in the country (sort of like G4).
As I showed above, cases differ. The best thing to do would be to have a decent GPA (3.5+). Therefore, you don't give the employer any reason to doubt your ability to perform on the job.
If you want to hear this from a college counseling expert who graduated from Stanford's Business School, I suggest heading over to Brightstorm's Facebook Page. They have a counseling tab where you can post your questions, and she'll go over them. Then she'll pick a few and post a video response. Other users are also able to help you, so you have nothing to lose.
http://www.facebook.com/brightstorm?sk=app_201792696507745 Have fun in college!