Support in LOL

Your general idea of the bottom lane

SUPORTTTTTTTTTTTTTTTTTTT....

You generally do not kill anything, until the situation calls for it.
When you start, you generally take one of the three items for supporting Relic Shield, Spellthief's Edge, or Ancient Coin, because they will be you main source of income.

Relic Shield lets you last hit a minion giving you and your ally closest to you the same gold
Spellthief's Edge lets you gain small amounts of gold by hitting an enemy minion, champion, or turret 3 times every 30 seconds, but if you kill a minion you wait an extra 12 seconds for that to happen, it also gives you 2 gold every 5 seconds.
Ancient Coin - gives you 2 gold for being near a minions death. So stay close to the minions.

You can only have one of these three items at a time.


Keeping ADC alive = this is your first main goal

Assists = this is your second main goal
Applying damage to the enemy in the same sequence as your ally has killed the same enemy. 
You do get gold for the assist.


During the laning phase, generally pre-level 8 or 9, you want to set up the kill for your ADC. Alert ping and chat for communication and better co-ordination.
For each champion has different styles.

Displacement Supports has spells that bring the champion closer to their allies (ADC) and away from the enemy support. Or they do not let champions move from a spot, which is the stun method.
This is the most common classification of a support there is, because there are many champions who can stun, grab and push. For a support mainly stun. These champions definitely can be mana hungry, so be careful how you use your spells. There also Displacements Supports that slow the enemy, making it hard to maneuver or get away
GOAL: put enemy ADC away from enemy support
Random tips: if you can use your displacements to force your enemy to stop what they are doing and escape. Better with stun. Make sure you tell your ADC that before hand, so they do not go in if you are going to do that. 

Second Tank Supports have more health and armor than the ADC giving the ability to take more hits. In the early game its not a lot more, but it post pones the enemy from getting kill that much earlier.
They are only the second tank because sometimes they will get an item to benefit their abilities to help get more damage of the engage of fights. These champions do not need to use as must mana.
GOAL: keep enemies distant from allies (ADC) and take more hits your allies (ADC) does.

Pokers Supports are generally hitting the enemy with their spells to lower their health, to push them away or have it easier in a fight. Some pokers do a lot of damage because their spells use AP, which the enemy laner won't actually have the items for because they want to defend against your ADC.
GOAL: keep hitting your enemy ADC in lane

Healers Supports, a.k.a buffers, are great because in times when their allies have taken damage sometimes even before going in, the healer support can give bonus armor, mana, speed, or health; depending on the champ.
GOAL: to keep giving your allies the chance to sustain (live) against enemies