[robertjflong]

You understand a usage of monads well, ie. using them to handle failing error states. However, in practice they are also used to deal with other side-effecting functionality such as state, IO, etc. If I was you, I'd look up the Monad instances for State, List, and a few others to get a grip on how you can model your own problem solutions using monads.

[biscarch]

Thanks for the tips, I've looked into the List monad, but I'm sure there are some useful ones I haven't looked into. Stacking IO Monads seems to be a useful topic. I'm also looking into Warp and Yesod for the req/res Monads.