Doses that I hear are often recommended for new users include the likes of Nitrous, Marijuana, Quick Happy, Crack... Most people don't get much a reaction from Nitrous the first SEVERAL times they use it. Marijuana Quick Hit provided me, personally, with instant and satisfying results.
I wouldn't recommend open-eye dosing for a while. Particularly for a beginner, your brain is still getting used to accepting the dose, like doing a math problem. Eventually, it'll "click."
In my experience, you always lose a massive bit of quality when using MP3s.