We have collected several documents here.
The first is a guide for PC chairing written by Julia Chuzhoy and Anupam Gupta based on their experience with STOC, and passed along to other chairs.
The second is a guide for general chairs / local organizers, written mostly by David Kempe but also thanks to Michael Hoffmann, Valerie King, and Yusu Wang.
We hope such documents will give more insight and transparency into what goes on behind the scenes in our conferences each year.
We do realize that there are technical details in these documents, some of which are obsolete and some of which may not be interesting to the general public, but we think such documents should be more well-known and we hope they will stimulate discussion in our community and give us ideas on how we can improve.
Please let us know if you have any comments!
Theory Matters 
In addition to these useful write-ups, we have written a “A Guide for New Program Committee Members at Theoretical Computer Science Conferences” which is available at https://arxiv.org/abs/2105.02773
Any comments and suggestions for improvement are welcome, and will be incorporated in future versions.
I can also recommend this guide for first-time PC *members*! https://arxiv.org/abs/2105.02773
Thank you both for the link!