I am writing a tutorial on how to use a specific web application and I don't know which verbs to use. Shall I use "click" for buttons? But what if the user doesn't use a mouse? Contrary to "normal" applications, web applications can be visited by many different clients, e.g. PCs, Smartphones with Touchscreens, Voice Recognition Software... But the verb "select" fits better for radio buttons and check boxes in my opinion and would not be best for buttons.
Also how should I emphasize different elements such as button names, radio button or text field labels, strings to type in from the user, select entries...is there a guideline anywhere?