Runes
AD Carry: As an AD carry you are aiming to deal as much damage with your auto attacks. Armor Pen and attack damage help you do this very well. Armor and Magic Resist help you stay alive throughout the game.
AP Carry: This is a defensive version of mage runes. The health and Magic Resist helps you from getting bursted down by other AP carries early game. The magic penetration will give you the extra buff to your damage, and the mana regen per level makes it so you won't need mana sustain items
Top Lane: This is an example of an AP top champion basically your runes are tanky except your marks which are penetration. So for example if you were an AD top then you would get Armor Penetration.
Support: Other than the quintessences, which should be gold per 10 it is a support page. This helps the support stay in lane and not feel gold deprived from letting the carry take the cs.
Masteries
Masteries are a fairly simple concept. at level 30 you have 30 points to spend in masteries and depending on your role, you will more than likely place them in a 21/9 fashion.
AD carries will go 21 in offence maxing all AD beneficial Masteries, with 9 in defence getting the health and armor masteries
AP carries will also go 21 in offence maxing all AP beneficial Masteries with 9 in defence getting the health and magic resist masteries.
Tanks depending on what kind they are will put 21 points in defence and either putting 9 points in offence specialising to get either armor pen or magic pen. You can also just put 30 points in defence to get that extra tankyness for champions like Malphite.
Jungles build very similar to tanks but they have Summoner's Resolve for smite and get the 2 points in tough skin so you can survive longer in jungle.
Supports put 21 points into utility and either 9 points into offence or defence. Supports should always get the extra gold per 10 masteries and the bonus gold at the beginning of the match. If the support does not rely on being tanky such as Janna they should put 9 points in offence to get the bonus magic pen. However for supports like Alistar they need that extra buff and should get the armor masteries and health in defence.
AD carries will go 21 in offence maxing all AD beneficial Masteries, with 9 in defence getting the health and armor masteries
AP carries will also go 21 in offence maxing all AP beneficial Masteries with 9 in defence getting the health and magic resist masteries.
Tanks depending on what kind they are will put 21 points in defence and either putting 9 points in offence specialising to get either armor pen or magic pen. You can also just put 30 points in defence to get that extra tankyness for champions like Malphite.
Jungles build very similar to tanks but they have Summoner's Resolve for smite and get the 2 points in tough skin so you can survive longer in jungle.
Supports put 21 points into utility and either 9 points into offence or defence. Supports should always get the extra gold per 10 masteries and the bonus gold at the beginning of the match. If the support does not rely on being tanky such as Janna they should put 9 points in offence to get the bonus magic pen. However for supports like Alistar they need that extra buff and should get the armor masteries and health in defence.