I recently setup a Nexus Pro instance on a Solaris zone for Apache. The ASF infra team requests documentation for any production instance to assist in maintenance down the road. I captured every step of the process from setting up the users, installing Nexus, hooking it into SMF (Solaris's inet.d replacement), to configuring mod_proxy and https certificates, and allowing rsync access from the Maven Central Repository.
In addition to serving as a server book for this instance, I think these docs are a great resource for users to see an end to end installation on Solaris (almost all of it is applicable to Linux as well).
I will continue to update these pages as things change and will also document exactly how I have configured the Nexus application as well, to show how to properly configure Repository Targets, Permissions, Staging Profiles, etc.
Here's the link to the docs, Enjoy.