After playing on PBE for 2 weeks, I believe I discovered the best possible spells, items and masteries for (ranged) supports. I'l briefly describe it here, and it will be improved once Mobafire does, I can't search for the items and it's a pain in the *** to scroll down alphabetically, tanky melee support coming soon.

The new support starting item is Crystalline Flask and 3 sight wards, you can also get Rejuvenation Bead or Faerie Charm, and later build it into philosopher's stone. After that you need the two money items philosopher's stone and kage's lucky pick. These will later be built into shurelya's revelry and Shard of True Ice. Another important item is banner of command], it's relatively cheap considering the fact it gives ap, aura and has a very useful active (esp. end game), which helps with your gold income. You'll also want [[runic bulwark, as it's the best aura item. After that, you could either stick with sightstone/ruby sightstone or sell it for Locket of the Iron Solari.

The important masteries are Artificer and Pickpocket , Biscuiteer and Explorer help too. Good thing is, they're all located on the same mastery tree. So build them without getting the useless masteries. Then you want health and defense, and as you can see, it perfectly fits. Artificer if important because at end game, a support should have 4 or 5 active items, now that Riot added around 50% more items. Pickpocket is really useful for getting gold while not stealing kills and cs, but only works well for ranged, so every 5 seconds, harass the enemy carry with a basic attack.