>>I am 3 months old hosting and recently had a guest complain that dishes and pots he used and left are not washed the next morning. I thought it was clear that guests wash their own dishes after use, as it is self catering and not a hotel<<
This person clearly expected maid service. He was wrong, you are not.
>>Do i put notices in the kitchen for guests to wash their dishes?<<
A line in your house rules should suffice.
>>I provide dish clothes, liquid dish soap and the likes for dishes to be washed. Is there more i must do like wash dishes for them?<<
Nope. You are not their maid.
Happy hosting, @Ncamsile0.