I purchased Mind Manager Smart and I do use it. It is easy to use and pretty intuitive. I wish the mind maps looked less childish and I would like the ability to draw links between two branches or to add text without a branch. Other than that, it's a nice program.
Some day, I'll get around to trying Ygnius. The ability to export a mind map to Microsoft Project is appealing.
A couple of interesting books on getting started with projects (that aren't "project management" books) are:
To Do...Doing...Done by Joyce Wycoff
Rapid Problem Solving with Post-It Notes by David Straker
Getting Things Done by David Allen