Recipe books are used to share recipes, give people something to work with and to use in their own home cooking. With the age of the internet and everything being online, is there still any kind of market for recipe books?
If you have something that can add to the market, it is still possible to release a recipe book and have some success with it. It often helps if you have your own brand, such as health, fitness or personal training. This means people will already know you and will be interested in the recipes that you have to share. It would be much harder to launch a recipe book without any kind of existing popularity or presence.
If you are starting out, then you should consider starting out with some online publications. This gives you a chance to get something published and to begin building up an audience and following.