The correct spelling of the two-word phrase "led do" is actually "let's do." This phrase is commonly used as an invitation to participate in a particular activity. The word "let's" is a contraction of "let us," which is pronounced /ˈlɛt əs/ in IPA phonetic transcription. The word "do" is pronounced /du/ in IPA phonetic transcription. So, if you want to suggest doing something with someone, it's spelled "let's do."