I'm not sure what type of link you want!
Computer speakers come in two types, 'passive' and 'active'. The passive ones don't have any amplifiers built into them; they're just speakers. (They're unsuitable for your purposes as you need an amplifier circuit, with a volume control - and preferably a tone control as well). 'Active' speakers have the required amplifier.
Deggers link is one possibility. Those speakers have got a tone control (which, given that you're trying to improve the sound, is highly desirable). The power output is 2.5W. Most hi-fi buffs would laugh at such a figure but it's perfectly adequate for bedroom use. In fact, having done a bit of googling, they're probably exactly what I'd buy if I had to buy new speakers - but so many charity shops now sell good quality amplified speakers for just a pound or two that (being a skinflint) that's where I'd actually start looking!