Knowing last year's questions or exam pattern may not help much as CEM is likely to change every year. I would focus on preparation instead.
Below is some information that I posted on other threads but useful as Reading, Kendrick and Slough use the same test(same day).viewtopic.php?f=70&t=41204
Berks exam has VR,NVR and Maths. VR = some elements of traditional VR(synonyms, antonyms) + English (comprehension + cloze). Most likely, VR is 50% of total marks, MAths 30% and NVR 20%.
For VR, add cloze, comprehension(multiple choice), synonyms and antonyms to your preparation.
For NVR, go through some 3D NVR(cubes,nets,series) in addition to your existing preparation. Although 3D NVR may not appear in some tests.
For Maths, thorough preparation up to level 5 and good amount of level 6 topics as well.
You may use a single publication to introduce topics but use papers from a variety of publications for the DC to get used to types of questions, accuracy, speed and stamina.
Try and do as many mocks as you can, including Sutton mocks (both). They really prepare the child for the exam experience and show the weaker areas very well.
Finally, my observation with berks was Maths levels were quite high or we were behind schedule. A strong English probably helped my DD to pull through.
Disclaimer: CEM exams are unpredictable and likely to change every year. Above Information is based on my experience and it may be subjective.
And this -http://www.elevenplusexams.co.uk/forum/11plus/viewtopic.php?f=70&t=41154
Although it is hard to compare 11+ with national levels, for super selective schools like HBS, Tiffins, Kendrick as a rule of thumb prepare your DD up to level 6 Maths/English.
Papers don't have to be CEM specific. If you look in the Shop section of this website you will find a variety of publications. Try and cover as many publications as you can moving from the easier ones to harder ones as you go along. According to last year's experience most of the DCs found CGP and Bond CEM papers quite hard so don't be surprised if your DC drops score on those ones. Bond(other than CEM), Athey, Walsh, Learning together, Alpha series, Bright sparks are easier than CGP. Doing them before the harder ones may help your DC to build stamina and speed thus developing readiness for the harder papers.
In my experience DCs pick up speed as their learning phase tapers and as they do more and more papers. May be after the first 5-10 papers you may notice a sudden rise in speed. You may not want to panic your DC by timing from paper no. 1. You can however discreetly time your DC and see which direction it is going with the next few papers.
Any other questions post here and folks here will help you as best as they can. Good Luck to your DC