Changing font size for menu and body

Hi. Just wondering which options to change in the style sheets (if that is the best way to do it?) that will allow me to make the font size slightly smaller for menu and body text. Either that or I would like to know how to remove the search option on the menu. It doesn't quite let me fit all menu options on the top line to keep things looking smoother. url: http://revct.org Thanks in advance!