Infinite product of a sequence of real numbers

I'm not sure what this is defined as, so I'm putting this here for lack of better knowledge.

I'm working on problems involving the infinite product of a sequence of real numbers, as well as a couple of proofs involving the infinite product of a sequence of real numbers. However, my current problem deals with solving the infinite product part itself.

I understand that you're taking the limit of the infinite product to get the result, but I don't understand how to GET the limit of an infinite product. Can anyone point me in the right direction(s)?

Real Analysis is getting to me. ;)