Dont know what to buy.
 

i have a nishiki frame i just bought. im pretty much a noob at this but im really trying to learn and do it all myself. my bottom bracket is 68mm 117.5 so could you direct me what bottom bracket to get along with a crankset to set up a single speed please. at least to give me an idea ya know. anything else i should know as well is welcome...

thanks guys

Take the frame to your LBS. Perhaps there is a bike collective in your area, or a place that offers classes. parktools.com has lots of repair info, and google sheldon brown. Have your LBS set up the bb and headset and go from there. Good Luck!

read: http://www.sheldonbrown.com/fixed.html
and then come back if u have questions :)