Need a patio but garden is boggy?

my garden is mainly clay, and get boggy when we get a lot of rain. i d like to lay slabs on an area of 10ft-5ft but don t no what to put down first so we can cement the slabs.I have lawn,decking and two other patio areas.the part i want to do now is just coloured stone.but the area would be ideal for the bbq,as its out the way and we have small grandchildren running around any ideas ?