What is obtained from the cross correlation plot?
I may answer things that you already know,but i will do my best anyway (i had similar problems once..).
When you do the Correlation of the two sequences you simply shift the one relatively to the other (as you may already know) so each time you shift it you get lets say one "dot" for your plot over there,one single point.This points in a row construct the plot you are getting there.Now,in order to get each one of them you perform one operation,lets say better one calculation which is:the number of equal/same bits minus the number of non equal/same bits,after you perform that you shift again and calculate again....Now when it come to the point that two identical sequences are perfectly aligned,you can understand that the number of "non equal bits" will be zero (cause apparently will be matching perfectly and the result will be a massive number (compared to the rest) that will be YOUR CORRELATION PEAK,meaning that you have reached correlation.As i see there that is something similar to BOC for satellite coms that i have been using in the past,is that case that time   you need to shift the waveform in order to reach to the peak is the time that you need to uses to calculate the distance in your GPS system!
I hope that helps...