If you want to print a particular web page you should first click on File and choose Print at which point you will be offered choice of printers to print to. If you choose the latter option you will be given the opportunity of choosing the name of the file you want to print to. It is a Postscript file and so it may be advantageous to have the file name end with with .ps. You also have the choice to modify the Properties of your print job. In particular, you can choose to alter the page size or you can modify print command and possibly a few other parameters (it is recommended that you not alter these unless you are already an experienced user, as sensible defaults have been configured in most cases).
Prior to printing, you may want to choose Print Preview in order to see what would be printed.