When sending letters to an inmate are there certain guidelines that need to be followed? Like things that you can and can not write? Example talk about intimacy ect..?

You can write all the intimate letters your heart desires. There is absolutely nothing wrong with that. What you want to avoid is writing about the case, the trial or any elements that could come back as evidence. The people that watch (and read) the mail are looking for threats and potential security breeches.