My background is as a developer, but I've been running my own business since 2008. For advice about business, I've always found other entrepreneurial developers are the best source, as they tend to have faced similar challenges to my own. If you're a developer starting your own business, the follow are some great resources for you.
Hacker News is an aggregator for startup / tech related news. It's been my gateway to most of the rest of the resources on this list.
Jason Cohen is an entrepreneur that has the combination of a developer background, and great writing and speaking skills. His blog is great, but his presentations are always what blow me a way. If you're getting started, I highly recommend "From geek to entrepreneur: Sifting through the Bull5h1t" and "Designing the Ideal Bootstrapped Business".
Patrick's heavy presence on Hacker News led me to his blog pretty early on. Being a fellow resident of Japan, and an occassional attendee of the Hacker News Tokyo Meetups makes him the only person on this list I've had the chance to talk to on a semi-regular basis.
I read Rob's book Start Small, Stay Small pretty early on, which although it is a bit dated, is a good into to the idea of Bootsrapping a software business. His weekly podcast he cohosts with Mike Taber, Startups for the Rest of Us is something that I regularily look forward too, and he also organizes Microconf, which although I haven't attended yet, has some great videos in the archives.
As opposed to the other resources, Brennan Dunn tends to write more about freelancing than building your own product. In addition to the material on his personal site, there is also some good advice on his product's blog.
Business of Software Conference
Along with MicroConf, the Business of Software is the best conference for developers interested in entrepreneurship (well, I've never actually attended, but enjoy watching their videos).