Over the last few years GW have been pricing themselves out of my (and many other people's) gaming budget as well as doing other very strange things to the community like threatening fan sites. The one thing they have been doing well recently though are their Masterclasses. These are 1 day courses run at GW HQ with a couple of their painting or sculpting teams. I've now been on three of these, Forgeworld Tank Weathering, Eavy Metal Painting and Introduction to Sculpting. Each came with a complete kit, all the materials, lunch, training and all the coffee/tea/biscuits you can consume in 1 day.
The Weathering Masterclass was probably my favourite as I had an immediate use for that one as I was working on my Chimera and this Demolisher. I know I have a various step by step guides that I wrote afterwards. When I find them, I'll upload them here