This is my first (and probably only) guide on mobafire. I'm a relatively new player that started playing mid-season 7 and I'm currently at gold 5.
I'm probably not the one to help you climb but I do know all rammus voice lines from just memorizing, so you might aswell just call me a pro Rammus main.
I dont usually play alot of jungle so I can't provide much general tips but I will try to explain some good things to know about Rammus.

Rammus as a champion is very good at locking down one champion and therefore it's more important to gank than farm, also it's very important to always get your taunt of so your combo works and your team can follow up.

Your W slows you and should therefore be cancelled early if running away from enemies, but in teamfights it should be activated as much as possible to make anyone trying to hurt you hurt themseves in the process.

Don 't forget that R also deals double damage to turrets and can be activated while in (Q) Powerball

With flash you can also make great ingages by using Q to get close and then flashing in providing an insant knock-up on multiple people if they happen to be clumped.
Then use R to get that sweet AOE slow and end it with an ez taunt on the carry into activating W to make them cry in all chat that "Rammus needs to be nerfed" or that he's a "brokan champ". (unless they buy QSS in which case you just have to hope they can't 1v5)

I'm not gonna go much more in-depth since this guide is mostly the basics and getting to know Rammus. Also don't forget to spam "OK" all-chat and it would be even better if you equipped the "OKAY" emote aswell.

Good luck and keep on rolling!

"OK" -Rammus

Thanks for reading my small guide and if you want me to spend more time on this guide it would be amazing if you could leave a comment and tell me on what i could improve on. It would also be very interesting to hear how this build worked out for you guys!

Lastly i want to give a small shoutout to "best rammus OK" who inspired me to do this guide. I've followed his guide on how to play Rammus for a long time but it seems like he quit the game as he's still lvl 30 and haven't updated his guide in a very long time, so I'm gonna link the guide here

Also i want to give some love to Pants Are Dragon that made me start playing Rammus when he still was META ;-;