16 inch rims and tires

ok so i found this nice set of rims that are 16x10 moto metal 951s(my truck is black, black chrome, NICE HAHA)...i have the stock regular ones(not trd) with just 245/75/r16 tires and i wanted to go up to the 265/70/r16 tires because they have like white writing and they look kind of better(i think they come on the stock trds). what i was wondering is are the stock ones or the other ones i mentioned the right size for the rims? and will i have to get balancing and other stuff done when i get them installed, if yes how much for installation and all? also what i notice is that i went from a 75 to a 70 on the second number, what is that? actually what do all those numbers mean haha i know that the 16 is the rim size but what are the other ones.
sorry about all the questions but im new to this
thanx guys

 

16x10 is a wide rim, most people either go with a 16x8 or16x9. I personally would not try to put either tire on that rim. Anytime you take the tires off of the rims you will have to get them balanced. I'm just going to link you to a website to explain the tire sizes http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=46 Good luck