I passed my IAM advanced riding test on Saturday 
I found the course to be very very good and it really helped me to improve my riding skills.
The way the course work is pay £139 to join the IAM for a year which also includes a years RAC membership and a couple of books. http://www.iam.org.uk/riders/riders-courses/advanced-riding/skill-for-life-motorcyclists
You are then allocated to your local group from this list http://www.iam.org.uk/iam-groups/iam-groups-directory/search
Your local group then allocate you an Observer. Your Observer will go out with you one to one and each 'lesson' can be between 2-6 hours depending on how much time you both have available. For my local group you pay the Observer £10 each time you go out. At the end of each lesson you get a sheet detailing how you did and what you need to work on etc.
As well as going out with your allocated Observer your local group may have group runs where you can go out for a ride or an observed ride. Your local group may also do full member runs but you can only go on these if you have passed your test!
Once your Observer thinks you are test ready you will have a check ride with a Senior Observer and if he agrees you can go for your test. The test consists of a couple of hours riding on various types of roads.
I think that about covers it!

I found the course to be very very good and it really helped me to improve my riding skills.
The way the course work is pay £139 to join the IAM for a year which also includes a years RAC membership and a couple of books. http://www.iam.org.uk/riders/riders-courses/advanced-riding/skill-for-life-motorcyclists
You are then allocated to your local group from this list http://www.iam.org.uk/iam-groups/iam-groups-directory/search
Your local group then allocate you an Observer. Your Observer will go out with you one to one and each 'lesson' can be between 2-6 hours depending on how much time you both have available. For my local group you pay the Observer £10 each time you go out. At the end of each lesson you get a sheet detailing how you did and what you need to work on etc.
As well as going out with your allocated Observer your local group may have group runs where you can go out for a ride or an observed ride. Your local group may also do full member runs but you can only go on these if you have passed your test!
Once your Observer thinks you are test ready you will have a check ride with a Senior Observer and if he agrees you can go for your test. The test consists of a couple of hours riding on various types of roads.
I think that about covers it!