<em>Edification and Beauty: The Practical Ecclesiology of the English Particular Baptists</em> by James M. Renihan
<em>Associational Churchmanship: Second London Confession of Faith</em> by James M. Renihan
These are the two that come to mind that are specifically confessional Reformed Baptist. For broader RB, contemporary takes, 9Marks has a lot of materials. Books like Jonathan Leeman's <em>Don't Fire Your Church Members</em> come to mind, but they have a lot more including articles and podcast on their website: https://www.9marks.org/
On my youtube channel, I started a series on Congregationalism (the first episode introduces John Cotton, a major Puritan proponent of Congregationalism). By the time I get to the third and fourth episode, I'll hopefully have some more specifically Reformed Baptist recommendations.
also tagging: /u/jordancda