The less players you face the better. You definitely want to raise, just enough to get one or two calls but not so much as you don't want to scare everyone out. So 3BB, 4BB, more or even all in ? In my opinion they are all correct and acceptable raises, it all depends on the table dynamics you are on. The faster the table and the more active and aggressive your opponents are, the higher your raise should be. And after all, no matter what your actions could be, you cannot predict what a donk or a maniac would do. I had my AAs cracked yesterday by 42 off, having moved all in after the guy had raised to 4BB !!! Go figure....