How to start a career in the startup industry?

Hi guys, I would be really grateful for your suggestions or opinions.

I am looking forward to work in the startup industry and contribute to the os movement. My background is mostly in Java, c/c++. I know that It is a long learning path (python, JavaScript, HTML, css, frameworks like django and pinax), therefore I am willingly to work full time in learning and getting experience.

To start, I have the following ideas:

1) Getting 6 - 12 months sabbatical.

2) Work as apprentice (for free) for a startup. Do you think that any startup is going to be interested in a work setting of Master/Apprentice?

3) Contribute to an open source project like Pinax (Django). could you recommend me another project?

What would be more constructive: working for startup or spending most of the time making contributions to an open source project?

Thanks!