Any quick tips to speed up a wifi network?

We have Verizon Fios and I think we're paying for like 100MBPS. There's 4 of us living here and none of us are overly pleased with the performance. We have all our smartphones, 4 laptops, an Ipad, 360, and PS4 all hooked up. Obviously that's a lot of strain but its rare for all of us to be using it at once and it's still kind of slow with only 1 or 2 people on. I get the worst of it because my room is a good 40 feet from the router and they are all closer.

I tried searching google on ways to tinker with the settings but I'm scared to mess something up. We are in a building with hundreds of other tenants so I'm thinking maybe theres just too many signals interfering.

Thanks for any advice.