Understanding Return Metrics

[Mark Jones]

Hi BP,

I'm trying to get a better understanding of return metrics. I don't want this to turn into a thread where people ask me what type investment I'm looking at and giving me the numbers. I want to get the mechanics behind calculating returns so I can learn to get the numbers myself. For example why should I target a X IRR as opposed to a Y IRR?

If someone can point me to some resources for this I would appreciate that as well. 

Thanks in advance!