Having sold Opsware to Hewlett-Packard recently for $1.65 billion, Netscape cofounder Marc Andreessen has advice on how others can duplicate his successes. Andreessen's recently launched Pmarca Weblog includes a "Guide To Startups" series that's worth reading.

Posted yesterday, Part 7 of the series is titled "Why a startup's initial business plan doesn't matter that much." The key takeaway is that an ability to rapidly adapt is more important than having everything figured out at the start. Andreessen advises entrepreneurs to get the business going first, then "aggressively seek out a big market" once the startup is going. His shining example: Thomas Edison's unplanned success, the phonograph.

Part 4 of the series is on "the only thing that matters" in startup land. What do you think that is? (Answer: the market.)

Andreessen tells us what's in the pipeline for his blog. They include an upcoming post on books for entrepreneurs and a series on high-tech startups.

There's also this on the way: The truth about reporters. Gulp.