I am big fan of mind mapping as a means of exposing thought processes and allowing you to develop your thinking clearly. Tony Buzan is as it turns out the inventor of mind mapping as an approach. I found this video this week from the CEO of ThinkBuzan who are selling mind mapping software based on his principles. There are many other open source and commercial offerings. So in order to help your children and express themselves and help anyone work through ideas, challenges or issues please look into mind mapping.
To see the transformation in understanding it can bring is inspiring, the see the release it provides for someone trying to express themselves when they cannot find the words or translate the words in their brain to something others can understand is emotional.
If you want to try out software that is free or open source or online then also try some of these