Hi ArnoldSiemsen, welcome to CFC!
There is no "print" button or function in-game, but what you can do is hit "PrintScrn" (by F12) and open MS Paint and paste it (Control + V). That won't allow you to read all the text though, if there's a scroll bar. You can read the whole Civilopedia, however, in your C:/Program Files/Firaxis Games/Sid Meier's Civilization 4/Assets/XML/Text/ folder, by opening the various Civ4GameText_Civilopedia files. This way is also more convenient because you can type Control + F and search for a keyword.
There's a lot of info that's in the Civilopedia available on this site (e.g. the
info center) too.