your first cycle will always be your best cycle you will experience in your whole life.
It seems most people put on about 30 lbs everytime.
After that the gains get harder to come by.
You need to take off time to let your body clear itself out by doing PCT.
Your body needs to learn to produce its own hormones again naturaly before you do a second cycle.
I would not start stacking until you really need to, like if you just can't seem to break through a plateau.
Keep your first cycles lower in dosages.
Don't take massive amounts right off the bat.
When you just start out , most people will respond to just about anything. There is no need to stack anything during your first few cycles in my opinion.
I am sure there are others that may disagree.
As far as doing another test cycle.Well if the first one worked, why not do the same thing again ?
As you continue to get more and more cycles under your belt, then you will probally start incorparting stacks into your cycles.
Just remember to take time off between cycles.
As a rule of thum I stay off for just about as long as I was on my last cycle.
You are gonna loose some muscle, it just comes with going off, but don't worry in the long run you will end up alot bigger in the end.
If you start taking GH you won't loose your gains , or will you have to cycle it .
Most people that I know that can afford it stay on GH year round.