[cle]

Clojure is definitely more practical, being much more widely used in production and running on the JVM (which provides access to a huge array of Java libs).

Scheme is simpler though, and probably more approachable for a beginner. The hosted nature of Clojure means you'll need a decent understanding of the underlying JVM to understand errors--the first time you get a stack trace you're going to seriously question your choice. Also Clojure's syntax is more complicated (but really, not at all complicated compared to Java, C#, Python, etc.).

You should be able to pick up Clojure pretty quickly if you're already familiar with Scheme, the programming style is pretty similar.