Olá! Eu conto os números de um à vinte em português. Hello! I'm counting from 1 to 20 in Portuguese. Please feel free to comment and correct anything to improve my pronunciation. (: I've never taken a course, just a bit of self-study.
I know there are many dialects of Portuguese, and the pronunciation only represents one of them. I'm aware that my pronunciation of 1 wasn't [u] enough, it was kinda more [o]-ish. And my 16 should have ended in a sh sound (IPA symbol ʃ ), but I said [s].
The symbols within the square brackets [ ] is the pronunciation as indicated by the International Phonetic Alphabet (IPA). It's a standarized system of phonetic notation that linguists use, associating one sound with one graph (letter). Once you know the IPA, you should be able to pronounce any sound in any language!
I'd be happy to explain any of the symbols. Information is also available on the wiki: http://en.wikipedia.org/wiki/Ipa