Usually you don't need to communicate landing a hook. You get a hook, the adc hits them a few times, and they either get away crying or they die. Any adc that doesn't react to a hook being landed should go play top lane.
The 3 best supports for low elo are Blitzcrank, which is a hook and isn't as popular in higher elo's without being good at predictions, Morgana who is an absolute god in the right hands with her long stun and zoning skills when you aren't timing that black shield so well to counter blitz and Leona, the full all-in dive master. Leona can be one of the most aggressive pre-6 champs in the game that can snowball a lane really hard for her adc. Her peel and cc are pretty damn good and her tankiness is always nice when she's diving a backline.
Other than those three, Soraka, Nami and recently Taric have been popular picks for me. I like Nami for her heals and poke as well as good peel. Taric I just like because he works dynamic angles. Imagine Graves short range burst as he dashes in with a charged up stun. Yeah, Taric and graves make a beefy combo to tango with. Even a Cait/Ali combo had issues with us. Speaking of Alistair, he's not bad if you can practice his WQ combo. It takes some time to get perfect. If you can flash+headbutt a squishy into your team at the start of a teamfight then you just got a huge advantage for your team.
I've been spamming Taric with great results, but that's just me. I have another friend who can't get Taric to work for him to save his life. I personally think Morg and Blitzcrank are the best for lower elo's. Spamming blitz isn't bad if you don't mind learning to hook and Morg can counter him if he gets picked against you. Short of Blitz, I'd go Leona and pick Morg into her when she's picked against you. I've ruined Leonas as Morg. They telegraph the dive, I fire a stun towards my adc and freeze her there for my adc to get a running start.