The first place to start start searching for information is the online manual. For almost all of the commands on the system there is a corresponding online manual page which contains information about the command such as its syntax, what options are available for its use (these are like fashion accessories, most commands can be dressed up or dressed down), known bugs, and if you are lucky some examples of how to use the command.
Access to the online manual can be gained using the man command. The general form of the command is:
% man command-name
As an example the command:
% man man
would display the manual entry for the man command. The manual pages are displayed using the command less as described above.
You will notice that to use the online manual in this way, you have to know the name of the command that you are interested in. If you wish to look for manual entries on a particular topic, try the commands:
% man -k keyword
% apropos keyword
Some topics have more than one manual entry, for example:
% man -k uuencode uuencode (5) - format of an encoded uuencode file uuencode, uudecode (1c) - encode/decode a binary file to transmit by mail
The number in parentheses is the section of the manual in which the entry is located. uuencode (1c) contains information about the program uuencode this manual entry can be read by typing man 1c uuencode. Whereas man 5 uuencode will get you information about the uuencode file format.