We all have our favourites, but I go with (for a complete start to finish)...
A good snow foaming (forget which foam I have - and this will soon be outlawed with the hosepipe ban)
Meg's Gold Class Shampoo
Clay bar - Poor Boys
Meg's Gold Class Polish
Poor Boys White Diamond (Black Hole if you have a dark car)
DoDo Juice Rainforest Rub
Bilberry wheel cleaner
Gummi Pflege for the rubber
Augo Glym Roof Kit (if yours is a roadster)
Auto Glym Tyre Dressing
That's a main wash - maybe all of that 2-3 times a year.
In between I use Poor Boys QD+ to keep the car nice and shiny.
(it's filthy at the moment though

)
Obviously you don't need to do all of that. If nothing else a wash and QD keeps it looking good.
Gummi Pflege is great for keeping the seals in good order.
ADD: This is much more useful, my "goto" detailing post:
GAZA62 - Summer Detail
