One important thing to remember is that if you hit an error screen, like this one, the quickest way to recover is to click on the Back button. (In Netscape, it looks like: ).
To get help from the browser itself, find the Help menu, near the top right corner of the window. In Netscape, select Handbook from the dropdown menu (or just press the Handbook button just above the viewing area); in Mosaic, select Manual.... This loads the online manual for your browser, over the Internet. Use the Home key to return to this Lab documentation.