The first command you should do with your newly created character is ``help rules''. Then, there are some other commands that are very useful in the beginning:
'help <command>' shows the help information for a particular command, so 'help who' would give you the help you need for using the who command.
You start the game as a puny little mortal. You have a level, that describes in general how experienced you are, and four ``stats''; Strength, Dexterity, Intelligence and Constitution. You start with the value 1 in all these. To increase your stats and your level, you need experience points. Basically, you can get these in two ways; killing monsters, or solving quests.