What kind of job should you get if you want to attend HBS?

I’m finishing up my Bachelors in Computer Science and will soon be taking the GMAT. I know that I will have to work for a while before I can apply to B-School but I wanted an idea of what kind of job I should be trying to get.

I mean besides a high GPA and GMAT score, what do they look for?

What kind of job experience do they want to see?

Does the company you work for matter?

Are start-ups a good idea?