Using images from a slide for the internet

You have to use slide scanner in order to transfer them to your PC.

The best ones are the ones from Nikon. However, they are expensive and you won't need it unless you are professional. You may also use flat scanners. But be careful to choose the one with slide/film adapter build in, otherwise you won't get satisfactory result. I use Epson Perfection 2450 Photo and happy with it.

When you get your scanner don't start immediately to scan your images. Factory provided softwares does not necessary provide best setting/solutions for perfect scanning. I would recommend you read some articles - available on the internet - to work out the best possible settings for your system. You may visit http://www.scantips.com/ to get more information.

P.S. This info may solve your problem of web showing. For good quality printing you need more then that. I will recommend you to perform deep search about printers and it's color management capabilty.