There are a number of useful things one can configure in and around KDevelop's built-in editor. Of more universal use is to switch on line numbering using the menu entry Editor -> View -> Show line numbers, making it easier to match compiler error messages or debug messages with locations in the code. In the same submenu you may also want to switch on the Icon border - a column to the left of your code in which KDevelop will show icons such as whether there is a breakpoint on the current line.
