It doesn't really matter, it's somewhat healthy to do that every once in awhile, but doesnt matter if it's the first charge or not.
When fully charged, drain it completely. Once it shuts off, plug it in, but dont turn it on. Let it recharge fully. What this will do is calibrate it, mainly to ensure that you get a more accurate battery life estimate, but it's healthy for a batter to go through a full charge cycle once in awhile, maybe once a month or so.