erlend, en Heather Meeker - esteemed legal scholar in open source licensing & commerce (i.e. sustainability) - has written a book that every single #OpenSource maintainer ought to read, now available for preorder.
From Project to Profit: How to Build a Business Around Your Open Source Project
You know what’s harder than maintaining an open source project? Making a living off of it. But it is possible, and it’s better than subsiding your OSS practice with a closed-source day job.