If your starting a new topic - yes there is. I am not sure about the length, but ALWAYS highlight whatever you have typed (if its long) and then copy it - so that you don't lose the post (it drove me nutts when this happened after typing tutorials!!!). I think its about 2-500 words or around there or something - its NOT that much i do know. In subsequent posts you can make it as long as you like (within reason!!!!).