I tend to rely a lot on YouTube videos and have hopped around all over the place. Some of my favorite resources are:
https://www.ketoconnect.net/ - They are very actively involved with the keto lifestyle - offer programs, have published cook books, have an active blog and very active youtube channel and lots of recipes
https://ketodietapp.com/Blog - A rather new discovery for me - lots of recipes but also informational articles. The primary blog poster/app developer turned to a low carb lifestyle for health reasons. A lot of recipes are geared toward both keto and paleo. I have also seen several recipes alterations to accomodate those who need a non dairy version. Also a youtube channel.
https://www.ketogenicforums.com/ Also a new resource I found when searching possible causes for a return to the constant fatique I had prior to beginning the keto diet. For the first couple months I felt fantastic - more energy, seldom fatiqued and seldom had the desire to nap. Reading the discussions helped me narrow it down to electrolyte imbalances and also an increased use of artificial sweetners. When I first started I tried to really limit their use but discovering some truly tasty "sweet" treats I had begun indulge more and more often in foods with artificial sweetners. I have cut back quite a bit on those "sweet" treats and the fatiqued feeling has diminished again. Since it is a forum, there is TONS of info and questions to sort through.
There are so many other blogs with recipes. I was surprised by the number and also the number of keto related youtube channels. If I am curious about how to make a keto version of something, I just do a google search and get several different possiblities.
The first two resources, of course, are hoping to make money. They offer special meal plan/recipe programs and cookbooks. I have resisted the temptation. There are so many free resources for recipes - even from those selling cookbooks - that I see no need to buy a book because it seems most recipe books (keto or otherwise) have more recipes I consider unappealing than ones I find interesting to try. I am pretty boring in my eating habits - never was fond of cooking- and like to keep it simple.
I am sure there are many other quality resources out there- - just not enough time to find and study them all. In the beginning, I did do a search for free kindle keto books and gained some decent background/starter information from them. Also Netflix has a documentary on a low carb/ high fat diet and the impact it had on some different medical issues - The Magic Pill. I found it interesting.