Originally for the beta, and updated for the final release, this brief guide from tonymacx86 explains how to create a USB installer for macOS Sonoma via the Clover and OpenCore bootloaders.
A detailed guide to install macOS Catalina on some PCs from the well regarded tonymacx86 using the site's own Unibeast and MultiBeast software. The site also has instructions to cleanup kexts after installation, how to upgrade directly to macOS Catalina from macOS Mojave on an older Hackintosh, and covers the macOS 10.15.0 (Supplemental), 10.15.1, 10.15.2, 10.15.3, 10.15.4, 10.15.4 (Supplemental), 10.15.5, 10.15.5 (Supplemental), 10.15.6, and 10.15.6 (Supplemental) updates, too.
How to install macOS Catalina using VMware on a Windows PC from newcomer TechsViewer. The same site has a guide to install macOS Catalina on VirtualBox on a Windows PC, as well.
This helpful video from Mark with Tech (no longer online) offers easy-to-follow instructions to install macOS Catalina (10.15) on a compatible PC with Clover:
Official hardware support for macOS 10.15 "Catalina" is modestly more limited than it is for macOS 10.14 "Mojave" that came before it. It also drops support for 32-bit apps entirely. Be certain to verify hardware and app compatibility before upgrading an older Hackintosh to this version of the operating system or buying parts for a new system.