I never heard of possum or of the patches you bought, Butches triple twill seem to be really good but you'll find what you like as you go.
I'd recommend getting some Sweets 7.62 copper cleaner. it stinks to holy He__, but it will verify all the copper is out by NOT turning blue when you apply it. Then you know your copper free.
Enjoy your rifle, and just read what is available on line when you get free time.
Here is a good site to get some quality info on what ever you like:
http://www.varmintal.com/arelo.htm
Also, you can type in what ever question you have into Google and search the results. After enough time spend on reading the opinions (that'll be about 20 years or so - take coated or uncoated rods for example...NO ONE knows which is better or why...really) you'll see trends and a common thread to what is true and what is some dime store gun wanna be talk shizzle....
ENJOY IT MAN, ITS A TRIP TO SHOOT ONE HOLE WITH 5 ROUNDS!