Sleep doesn't do anything towards moving info from short into long-term memory.
I just described it in the dumbed-down "I'm not a scientist" way it was described to me in this one class I took.
Below is a website that lists abstracts of several research reports that describe the role of sleep in memory:
http://www.memory-key.com/NatureofMemory/sleep_news.htmThe site also includes links to the full-text journal articles, however many (if not all) require a subscription to view.