Hi Mazie,
Viggo is pronounced like this in Danish:
VIG - like English wig, just with a v-sound instead of w
go - with a short plosive behind the short o-sound... difficult to explain, but you can listen here:
http://www.speakdanish.dk/html/pronunciation_aeoeaa.htm
Listen to the last example (gå) - that's exactly how the second syllable of Viggo sounds like.
The stress is on the first syllable.
Regards, Satu