I feel like I'm all over your questions lately! A quiet few days in work so I'm on here probably more than I should be...
What that guy said is rubbish, get good microfiber cloths! I must have 200 at this stage and every few months I wash them all in one big batch.
Start building up your collection of them. Not all are equal, go for a good quality one but expect to pay around €10 for a 5 pack maybe.
That turtle wax is proabably worthless. Get proper solid car wax. I personally recommend autoglym super hd wax. One tub will last 1 - 2 years and it costs €50. That liquid car wax will just wash off after a few downpours.
I have the demon foam and it's great stuff but you need the lance and a proper power washer to get a good thick foam!
The autoglym shampoo smells incredible but gives you no suds (not necessarily a bad thing).
I'm sure there's a few detailing places in the uk people use such as cleancar.co.uk I think
Get a microfiber drying cloth for one and a lambswool wash mitt. You're also going to need 2 buckets and a grit guard.
Don't go near your paintwork with a sponge!
Take a look at my guide -
http://www.mk5golfgti.co.uk/forum/index.php/topic,89106.msg902491.html#msg902491