GH is a great tool in muscle building development due to its inducement of hyperlasia (splitting of muscle cells), I have not yet used it so I cannot talk about it from a personal stand point.
A cruise and blast is where you run 200mg of test in between cycles (in this case called "blasts). When you are ready to start your cycle you start it then when your cycle is over you drop down to 200mgs of test and you stay at that for a couple of months (or longer depending on your goals/experience/etc.) than you "blast" again (run your next cycle).
I should tell you that cruise and blast are done by only those who are older and more experience because you are basically shutting down your natural test forever so I don't know your age and your experience but cruise and blast are generally run by veterans who want to get more out of their cycles and keep gains and who hate coming off and PCT'ing.
Search cruise and blast and you shall find some threads on here with good infromation.