I think it's worth reading a post by akpanto - My journey through the 11 plus. I found it very useful.
Do you mean viewtopic.php?f=18&t=21392
It looks really good!
From our experience the important is to get started early with something like Bond (we used some Athey), then start timing, learn more about the exact types of exams, eventually broaden the types of books and before the last couple of months start introducing real tests from similar schools - plenty of them are online. One hour a day will probably be enough if over a long time.
Depending on how busy you are, what you can and cannot help with etc, you may want to take the time to select a suitable tutor early on.
Doing a mock test day is also very useful to get all the logistics right well before the day and train simple but often important stuff like not getting distracted by noises or other children and making sure there are no avoidable toilet runs during tests. Depending if you will try indies, some interview practice is useful. And generally paying more attention to what DC is reading (any newspapers?) and specially watching on TV helps.
The other thing is to decide early how you will handle the social pressure and jealousy that will start to build specially if you are in a school where most children will go to the local comp. We decided to only let people trying the same type of schools know, it kept everybody happier.