Start by having a look here
(this relates to the Birmingham exam but it is also CEM and the style format are the same as Warwickshire.
Broadly speaking - work on vocabulary. Verbal reasoning isn't conventional verbal reasoning - there will be multiple choice comprehension, cloze tests (pick the appropriate word to fill the gap, or possibly fill in the letters to complete the word), and others which are also likely to test vocabulary.
Maths - look at long, worded, multipart questions. They call it "numerical reasoning" not maths for a reason - half the task is working out what the sum is.
Non verbal reasoning - use any standard NVR to prepare, but try for as much variety as possible to be adaptable for different formats which might appear on the day.
Format is 2 x 45 minute tests on the same day, with a short gap between them - each paper has a mixture of the subjects, but is split into timed sections, so they can't move ahead, or go back to questions outside of the section they're on at the time.