Wow thank you guys for being so active on my game, it's an honor!
About the sewers, exactly like SpontaneousHiccup mentioned, as well as the blueprints, right now there's only a book for Handcrafting, Tailoring and Blacksmithing. There is no book for Cooking recipes yet, so yeah right now it's all about trial and error.
Currently there's 7 blueprints for Handcrafting, 3 for Blacksmithing, and 1 for Tailoring.
By the way you can craft Lockpicks through blacksmithing with 1 Iron Scrap ;)
For Cooking there's currently 21 recipes.
One tip for cooking/crafting: When you are cooking for example, you see a spoon stirring the ingredients right? While it is cooking try clicking on it multiple times to keep stirring, that will boost your chances of a successful crafing/cooking. So you may be having the right combination, just need to stir it up ;)
The animals you have to raise them to their adult form, to produce something. When they are in their adult form just keep feeding them and keep them happy until they produce their stuff, like the sheeps producing wool ;)
The rest I think SpontaneousHiccup covered it all for me haha.
Thanks!