I posted this at The Fatherhood's Discord channel but decided to share it here as well so that it doesn't get lost. These are different documents that I went through multiple times when trying to figure out how to find yet undiscovered signals.

Canonn Research - Odyssey Family

Link: https://canonn.science/codex/odyssey-family-familia-odysseae/
This article describes the basics of the exo-biology. I think it's a good entry point. You can learn about nomenclature, conditions for spawning, variant determinants, distributions, etc. Plus, at the bottom there are links to articles for each genus which are very useful for when you want to see, e.g., how colors of each genus depend on stellar classes.

Canonn Research - Get Your Name In The Codex

Link: https://canonn.science/codex/get-your-name-in-the-codex/
What the title says 🙂 If you want to get your name in the codex for finding a bio-signal that nobody has ever found before in a given galactic sector, you should read this. This will give you a rough idea of what to search, where to search, and how to search.

"Canonn - Surface Biology" spreadsheet

Link: https://docs.google.com/spreadsheets/d/15lqZtqJk7B2qUV5Jb4tlnst6i1B7pXlAUzQnacX64Kc/edit?pli=1&gid=0#gid=0
This spreadsheet has lots of information, but for my purposes I used only the "Regions" tab. What it shows is how many times a given species was scanned in a given galactic sector (these counts are only from the cmdrs who share their data using 3rd party tools). This can give an idea of what signals have high or low potential of being found in a given sector.

"Elite Dangerous in Game Codex" spreadsheet

Link: https://docs.google.com/spreadsheets/d/1uOYgECrwpIeYsapUxfOuULCeLAwIv_3ZqtNIvNDHsFA/edit?gid=2067105483#gid=2067105483
This spreadsheet is from the author of the "Get Your Name In The Codex" article who every week manually(!) checks the in-game codex and updates this table with new entries. For my purposes, I was using the "Visual All Items" tab that shows in a very convenient way the gaps in the codex. You just might want to filter the view to show only the bio-signals. There is also an interesting tab "Odyssey Bios/Week" that shows the evolution of the "bios found per week" number. And if you are searching for a truly galactic first, you might be interested in the "Missing Colours" tab. I haven't looked into it myself yet 🙂

"Codex NSP and Bio requirements" spreadsheet

Link: https://docs.google.com/spreadsheets/d/1nV_UD_0kIxkWAHhAqvf62ILHpbYzdZpJ53CqPHn3qlA/edit?gid=344475511#gid=344475511
You might want to refer to the first tab of this spreadsheet to learn about conditions of spawning of various species.

"Elite Dangerous, Undiscovered Odyssey Biology Count" spreadsheet

Link: https://docs.google.com/spreadsheets/d/1TpPZUFd61KUQWy1sV8VhScZiVbRWJ435wTN8xjN0Qv0/edit?gid=1228232201#gid=1228232201
This shows how many signals are not yet found in a given sector for a given star class/material. You could use that, for example, when you traverse a galactic sector by applying a filter to your route to use only the stars from the list.