National Debts

[Gumba Masta]

I've been searching for a good source that keeps a record of national debts of countries and with the internet being what the internet is I've been drowned in information so while I'm trying wad through the mollasses of numbers and stuff I wanted to ask if anyone here may know a good site that might help a layman (hurr hurr I sad lay) like me to understand what terms like "external national debt" and the like actually mean.