First up, there's a pretty good rundown of Mind Mapping applications. I don't disagree with their assessment, but I also reserve the right to prefer iThoughts as my primary tool of choice. You pretty much can't go wrong today with one of these options.
I'll also add MindMeister as a really great multi-platform tool that also has solid collaboration features. I use it when I'm on Windows or if I need to share with someone else. The new MeisterTask platform is off to a good start.
Next up, here's a nice presentation by the developer of iThoughts. It's mostly about learning about your place in the market and developing a sustainable and rewarding business. Craig Scott has been on the iPhone almost from the beginning and iThoughts may be the only app that has stayed on my home screen since 2008.