This little piece of hardware does wonders for people who do not want to use their onboard soundcard, or are beggining to record non-acoustic instruments. Also, with it's inputs, you can connect any mixing desk to your computer: record a jam session with ease, or your own experimentations, one layer at a time :)
Superb quality for the price, used it for years without problems, as it's pretty much Plug&Play!
This is where to begin.