I will be spending two months in Belgium and will be calling USA regularly. Where and what kind of a phone/prepaid plan I should buy. I bought an AT&T (unlocked) go phone and was wondering if I would be bale to buy a SIM card that I could use in it.
You might have a problem operating the AT&T Go-phone in Europe, depends on the phone model. Usually they sell older simpler dual-band phones as Go-Phones, and these phones won't work on European GSM frequencies. You need a 3-band or 4-band phone (sometimes described as "world phone" or "international phone"). Check with AT&T (or online by the model number) if your phone is of that kind.
If it is, and is unlocked, then any Belgium GSM provider should work. They have pre-paid SIM's there as well, but can't tell you which one and for how much as I used my own iPhone with the AT&T SIM (paying tons of money) when I was in Belgium.