Lead/Potential Source Analysis

Is there a way of tracking the source of a lead right from initial lead generation through to sale? And visually showing this in a graph?

For example

10 leads from google search

20 leads from event

5 google were converted to potential

11 event leads were converted to potential

3 google leads resulted in job

5 event leads resulted in job

I seem to loose data when lead is converted into potential and finding it hard to track. Also seems as if there is a lag and it doesn't update all data?