From what I have read about the SET NAMES this is an instruction that would be executed by a client connecting to a server to inform the server of the character set the data is being sent and what it should be returned as. If your db is all setup for UTF-8 and your charset on your pages is as well then you should not need to use this extra command since all the data will be UTF-8 anyway. One other thing that a colleague pointed out is that when you use UTF-8 the string searches performed will be case sensitive. This is different from using the latin-1 charset which is not case sensitive when doing searches. Here is a link to an article that discusses this:
case-sensitivity.html
