To display any output one screen at a time, then pipe it into one of "more" or "less".
For example: <command> --help | less, or <command> --help | more
For more, then press enter to move down through the text. For less, use the up / down arrow keys. To exit from both of these (and from man), press q.
You can send output from any command into a file, using the > operator, for example man (command) > file.txt (warning, this will overwrite file.txt if it already exists - to avoid this and add the text at the end, use >>). This file can then be viewed in and printed from any text editor.
Info files are yet another source of documentation for common commands. To view them, just type info (command). Once again, use q to quit.