You'll need C13 to C14 cables.  I have the 14AWG (gauge) ones.  Business rackmount servers come with these as well as the standard cables.  My dad's business had a bunch of extra ones.  

http://www.ebay.com/sch/i.html?_odkw=c14+to+c13+14awg&_sop=15&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xc13+to+c14+14awg.TRS1&_nkw=c13+to+c14+14awg&_sacat=0


I was going through the same troubles as you trying to figure out the proper electrical setup.

This link really helped me figure out what I needed.

https://bitcointalk.org/index.php?topic=74740.10