Really green pool Please Help!

My pool is really green & really dirty. I have not cleaned the pool in 3 years, we got all of the leaves out & the pool is really green I have bought one of the salt water systems but I have not hooked it up yet I want to get the pool cleaned first I have another pump that i am using first could anybody help... I have shocked it but it doesnt seem to help

In order for anyone to give you helpful advice, you'll need to provide a bit more information:

+ What type and size pool do you have?
+ What type and size pump AND filter do you have?