From the VoodooPad Help File: "Try not to organize too heavily when you are initially adding information to VoodooPad. Start throwing things in around a loose framework. As your document grows you will want to spend a little more time cleaning things up. If you impose too much order too early, you may find it difficult to get started. Avoid having multiple documents when you start out. VoodooPad is great for keeping multiple areas of your life together in a single document for easy retrieval."
This is good advice for any wiki. A loose framework is better than tight organization—especially at first. A wiki is not a relational database. Nor is it an outliner. Structure should emerge, not be super-imposed at an early stage.