I use Slideshare finding quick information from new topics and also new presentations on social media. I also follow some top names on Slideshare and embed presentation to my blog. You can make different kind of searches from presentations like most views, latest and favored, most downloads, browse by category and filter by type (presentations, documents, slidecasts, videos.
Part I tutorials presents basic use of Slideshare, Part II show how to make Slidecasts and Part III presents Zipcast in action.
Part I - Basic use of Slideshare
Slideshare: Why should you use it by Amit Ranjan
Part II - Slidecast
Slidecast tutorial: Creating a Slidecast
Part III - Zipcast
Introducing Zipcast by Rashmi Sinha