Ask HN: Good source of education on building an independent consulting business?

Periodically we see topics on freelancing and consulting, and usually a few people comment that they are successful and happy as solo (or self-owned firm) consulting. And often, those people stress that a good percentage of their time is spent networking and marketing to keep business flowing in.

Can anyone in this situation recommend modern, high quality resources where one can learn the networking and marketing skills to use to build a successful solo tech/dev consulting business?