The assessment day verbal reasoning tests are pretty representative of those you will face on the day but by no means the same. I personally feel that the test passages are slightly shorter but, sadly, no less ambiguous. More complex passages are loaded at the front of the book so if it looks like a ridiculously complicated passage then move on, as time is tight, and return to it if you can.
The maths test is simple enough. It doesn't matter how you dress it up in the end all maths boils down to addition, subtraction, multiplication or division. Make sure you can do those and you can't go far wrong.
Aplusmath.com gives you online work sheets of varying difficulty. Select a 30 question worksheet and set yourself a time limit. The key is working accurately and fast and the only way to do that is practice!
Good luck.