Luciano,
I expect most people export to outlook and check their tasks off there. You might try that - I find that ListPro is the best pda checklist app by far. (altho Bonsai is pretty good) I have quite complex projects with many hundreds of sub tasks. My method uses "promoted" sub topics (ie each with their own "page") and have many branches off each. Some are tasks, some just intel. When something becomes a job I activate the tickbox, and then export todos through the whole map into text. I then drop this into XL or Listpro and do the working off from there. The name of the promoted map sticks with each task, so you can autofilter on it.
It's worth reading up on possibilties - www.43folders.com always has lots of ideas: many people find the ways of working with a mindmap to be very different to a linear todo list. For instance; I have a floating branch marked "X Done" and at the end of the day I rip off completed tasks and drop them in there. Sometimes I use "X" or some other graphic instead of using the todo box, as it is easier to turn on and off. You can set the Taskview to filter on symbols or keywords, et so you can work whatever way you like..
While there are many, many approaches you can take, I would like to say that I'd like to see other ways of exporting data from the task list than just Outlook. A CSV export would be a great help, as would the option to export category info and etc.
Good luck!