Compojure is pretty standard for routing on top of the simple Ring abstraction.

I start projects with the template:

    lein new compojure my-app

Ring quickstart: https://github.com/ring-clojure/ring/wiki

Ring API docs: http://ring-clojure.github.io/ring/

I like bidi's data structure oriented idea. https://github.com/juxt/bidi

If you're just looking for a starter kit with everything included, consider Luminus. It gather a bunch of libs together and shows you how they interoperate to handle web requests.

One library that is pretty neat:

https://github.com/ztellman/aleph

Shameless plug: If you need really-fast route matching, consider https://github.com/kumarshantanu/calfpath (performance benchmarks are included)

FYI - various recommendations are made in this Clojure radar: https://juxt.pro/radar.html (disclaimer, I was an author).