Despite adding several new characters, ships, and worlds, I have attempted to remain as close to canon as possible. To enable that, I routinely use the following resources beyond the actual episodes/movies themselves:
Memory Alpha – An immense encyclopedia of all things Trek.
Stellar Cartography – My preferred map of the Star Trek universe. Because the original writers did not work from a canonical map and because the ships often moved at the speed of plot, it is impossible for any one map to wholly, accurately reflect the Trekverse. However, I find this one useful and comprehensive, so even though not every show-based location works on this, it is my favourite and I go by it whenever possible. Further, I have picked locations for my own created planets based on this map, and details of those will be included in each story’s download pages as needed.
Ex Astris Scientia’s Treknology Encyclopedia – For when Memory Alpha doesn’t have quite enough nerdy science detail.
Stardate Calculator – Calculates regular Earth dates to Stardates and vice versa.
Star Trek Travel Calculator – Based on the Stellar Cartography link above.
Star Trek: The Next Generation Technical Manual by Rick Sternbach, Michael Okuda – out of print but I’ve had it since the show as still on the air. Looks like you can get it second hand from many places. It’s my primary tech resource for everything to do with the Enterprise D and general technology such as transporters, replicators, shields, etc.
Star Trek.: U.S.S. Enterprise NCC-1701-D Blueprints by Rick Sternbach – also out of print, but I found a second hand set online easily enough for a decent price. I then made pictures of them so I could digitally alter them to make notes as needed, and combined with the room numbering/internal co-ordinates system listed in the Technical Manual, I’m able to choose rooms as needed and keep them consistent. They’re not perfect and are missing several canonical features, but they’re a good start if you’re looking to build an Enterprise-D based world.
The Nitpicker’s Guide for Next Generation Trekkers Volume II by Phil Farrand – I believe this is also out of print but again, I easily found an inexpensive second-hand copy online. I use this to go over the episodes and see a) if I’m the only one who has noticed a continuity error or other inconsistency to determine if it’s just me or what, and b) to find other errors I hadn’t noticed myself. Sometimes I ignore the issues, sometimes I nudge them a little to make better sense, sometimes I wholly re-write them.
In order to write descriptions of original characters and feature them on cover art as needed, I initially used Generated Photos to select for specific traits and then followed paths to create younger/older versions. That site does not use external sources for its AI, but rather in-house, professional photographs of actual humans. That said, the images I selected back in 2020 and 2021 were before generative AI had emerged as a severe ethical problem in that most AI does not use in-house data but in fact scrapes it from elsewhere without permission or compensation. That was also before most folks (including me) knew that AI comes with a high environmental cost. So although I continue to use some of the images I’d already used on previous covers or for character descriptions, I am now in the process of transitioning away from these images and going back to either celebrities whom I believe would not be offended by the characters I’ve written for them, or in the future I may move to non-photo based covers entirely. I have not downloaded any new photos off of Generated Photos since late 2021, because even if they are an ethical producer I’m concerned about the environmental effects. I remain staunchly against any AI products that scrape and steal. I have never used a text AI generator of any kind and have no intention of ever doing so.