Well start out by saying "Hi" or "Hello" and introduce yourself. Follow that with what made you interested in wanting to talk to him. Generally one should introduce yourself in a message first saying a couple things about yourself and what it was about him that interested you. After he replies, ask if he wants to chat the next time you are on line at the same time. Otherwise, just click to chat, and say "Hi read your stuff, would like to chat."

actually i wouldnt say hi or hello...i'd say heyy. hi and hello seem really awkward to me....wen someone says heyy it just seems real laid back n chill...like ther not gunna b difficult to try n hav a convo with. <3 peace.n.love.haylee