I have never heard this word before, but the Wikipedia article insists:
The word is also used to pejoratively describe those not of Jewish descent. It is commonly used to refer to Christians and Muslims, but is regularly used by Jews to refer to any and all peoples of faiths other than Judaism.
In English, the use of the word goy can be controversial. It is assigned pejoratively to non-Jews. To avoid any perceived offensive connotations, writers may use the English terms "gentile" or "non-Jew".
Looking at where the word comes from, it seems to be a benign word, equivalent with Gentile.
In common use, would Jews use this word among themselves? Is it regularly used negatively? Would they use the word among non-Jews?
I just noticed "goyim" in the tags, which is a word I have seem. My understanding is that would be the plural form of "goy". Is this right?