You might off by watching this presentation, which was recently webcasted by Lending Club to lenders. The 30 minute presentation lists benefits and explains the basics on how the website works.
Since it is marketing material it does show a very rosy picture on the numbers, but you can crunch all figures for yourself on Lending Club’s statistic page (e.g. change observation to loans issued from June 2007 to June 2008).
If you are ready to start investing at Lendingclub. com you can sign up here.