People tend to think that support is a braindead job, although it is being done so badly so often that I feel that it's important that I bring this up:
Listen, if you are support, and yes, I know it's boring, then your job is to provide map visibility as well as helping to keep your AD alive.
That means: Get a few GP5 items, then buy -wards-, wards, wards, wards. Try to slowly edge towards some Aura items, Aegis, if your team needs some defense, Zekes, if your team has a lot of AD champions, (Don't get soulshroud. Bad item), Shurelyas is good if you need to get in and out of action fast, but wait till you upgrade to this item for a while, because you'll lose 1 GP5 item in the process (and you'll feel it). Will of ancients if your team is AP heavy.
Also, if you are support, learn to counter ward. -THIS- is important. Your jungler cannot gank, if you're not getting rid of the enemy wards. You're also supposed to sometimes encourage your AD to let the creep wave up and move closer to your tower, giving your jungler a better chance to gank.
Don't play it braindead, and don't go for support if you want to actually play AD/AP/etc. I've lost too many matches because of AD Kayle bot with AS Lulu, trying to outfarm each other, where no one ever buys a single farm. (I tend to jungle, if I'm not support, so this -hurts-).