Please tell them ALL the relevant information- we need to know if your child sleepwalks or has night terrors, isn't dry at night, is terrified of cats and dogs, only eats one particular type of cereal (and will hyperventilate if given another) and many other examples.
Please don't be embarrassed (we have heard it all and more before) and it is so much easier to deal with and less distressing for the child, if we know beforehand.