These are either good for the newbie, or not very clear.
Terms to know
wimpy. This will be the first thing you should type. It will make you run away from a fight, rather than die.
legend [character]. This will tell you how old a character is (very important). Say you meet JonDoe the Dunedain Orc-Target and he is 8 days old. Run. Run fast and run hard. He is an assassin :).
Thought I'd break up the 'only text' stuff a little :)
tell [character] [message]. This lets you say things to people who are not in the same room as you are.
semote. This is a list of all the things you can "do". For instance Smile, Grin, Burp, Fart, Slap...
take all from body. This gets all the gold, weapons and other stuff from a body you just killed.
skin body. Skins the body of the animal you just killed.
shape (while fighting). Tells you how your opponent is doing.
tellhist. Very usefull. Tells you the last few things other PC's have told you.
pull brand from fire. A trick I learned rescently (Thanks, Antknei) you will pull a brand from a campfire, so if you can't find any torches, just camp.
[number][direction]. I just learned this, very cool. (hey, I'm new too.) ex. 10w will take you ten spaces westward.
chfn. This is so you can change the name on your legend, and the email address. It's kind of cool.
alias. I'm supprsed at how many people don't get this. Just type 'help alias', it's very useful.
look [item] in [char.]. This lets you look at items people have on them.