'Sonia', Patricia will probably come along soon and give her excellent advice
however for me I literally started at the beginning ... Question Type A and read the information from the method and technique book with my DC so they understood the instructions too, then followed by a question type A practice sheet. I then moved on to Type B and so on. IPS Starter Series book, Verbal Reasoning, Book S and IPS Verbal Reasoning Additional Practice, Book C are excellent for this.
Now I'm happy my DC is confident with all the question types, I am now doing the Tutors papers (you can download these from the elevenplus shop), starting at the easiest level (1) to boost their confidence and will gradully work through to the higher level. Although I understand Tutors Level 4 and quite high and may leave those till later. Plus I am also starting on the IPS Verbal Reasoning Practice Papers, book A; these have 50 questions and cover a mix of the question types.
Once I'm happy with this level of tests I can then move on to the next level as recommended by Patricia
Don't also forget about vocabulary (very important for Bucks 11+). Patricia has put together some exellent word lists which I am gradually working my way through with my DC, learning the meaning of words (which may seen obvious to us but not a 9 year old) and how how these words work with other words.
Hope this is of help?