This source is a great opening to forms because it lists and describes the different components of forms. It also shares elements that greatly help users navigate forms such as input masks, eliminating unecessary words, label alignments, and other aspects of form design that help with usability. Overall, it is an explanation for web designers to know what to include and what to eliminate in the forms they create.
This source goes over what is the most effective when designing a form. Web designers should acknowledge factors that will make their forms more user-friendly. For example, this source tells the reader to avoid asking for phone numbers in their forms and to allow for an email option instead, for phone number requirements drop user sign-ups by nearly 40%.
This sources shares different kinds of forms and some of the best examples of form design. It shares some of the factors in the well-designed forms that may help the reader understand what it is about these forms that work. This is a great source for gaining inspiration about all the form possibilities.