Lulu is mainly support but due to Glitterlance and Help Pix doing quite a bit of damage at the moment this build utilizes the damage of Lulu but still stays as a support.

8/0/22 is probably the best choice for Lulu, once again being a support you shouldn't be getting CS therefore increase gold per second is great also more starting gold with Wealth would get you ahead at level 1. You should then put points into Mana Regen and increasing your Mana pool as you should be harassing heaps all game.

Putting two points into glitter lance relatively early in the game is great for harassing and keeping them constantly slowed, as a support this is exactly your role. Then max Help pix along with Glitterlance so you can be shielding your teammates and using it to further the range of Glitterlance and also doing a bit of damage. Whimsy is maxed last as you only use it for CC and Speed boosts which don't change much with levels.

Rushing an early Philosophers Stone is essential to keeping up with gold as a support, remember no CS which means you compensate with increased gold per second. When you B you should have enough to finish your Phiolophers and hopefully be able to afford boots. You should build a Catalyst next to keep you in lane and an early RoTA will get you max stacks early on. A Shurelyas for team fights and a Rabadons to keep your AP up mid-late game. Then building a Banshees veil is great for survivability and a Guardians Angel also as a dead support isn't very useful. A Rabadons is also good as it means that the opposition would need to kill you twice which gives your team more time to kill them.