Both the slough consortium (Langley, Herschel & St Bernards) and Slough Grammar use an exam set by NFER - Multiple choice - VR, NVR & Maths
Have a look on the '11plus advice' on the home page(left hand side column)
If the board is NFER, then IPS & AFN provide good preparation books, as do the NFER papers themselves.
There are only 4 sets of NFER paper so these are good for nearer the time to see how the timing is going, but it is possible to use them in the beginning to see where there may be gaps in knowledge (espec Maths)
I believe this site also has papers that are very similiar to NFER and also offer some CD's (it can take the monotony out of aways doing the paper practice). Give them a ring they are always willing to advise.
I don't know about Reading Grammar but I am sure there will be someone around later to give you an idea....I think there was a post not so long ago that might help.
If you also look at 11+ regions (home page .. left hand column again) and click on Berkshire it will give you an overview.