No worries

Now first we need some of that apple flavored lube...
Oh sorry, with the game.
Arr...
Ok, in short. Your a little 2D dude. You've got some basic tools. By day you will be attacked by slims. By night you will be set upon by zombies and flying demon eyes.
So cut down trees with an axe to get wood & acorns. Collect mushrooms for a +20 health.
Dig into the ground with the pick axe to get dirt / clay / stone.
If in doubt & it's getting dark, dig hole. Seal up hole. Wait till daylight.
Pressing "Escape" brings up stuff. The top row is a kind of action bar. You can move items on to it and keys 1 through 10 will hot pick them. So Dig into ground and get dirt. Press escape, move your dirt blocks onto an empty slot. Press escape again to make the interphase go away. Now you can either select the option from the top left bar with your mouse pointer, or press the corresponding button. Now you can start arranging blocks.
Hang on, your gonna need a work bench. And a chair. And a table. OOO! A forge is good. An anvil is gonna take a while. Oh the joys of crafting

When you press escape, in the bottom left of the screen is the crafting options. This shows you what you can make, and what bits you need to make it from the stuff you have. You can use your mouse wheel to scroll through the list.
I'm probably not making much sense.
Here's a helpful guide...
http://terraria.wikia.com/wiki/Starter_guideYou can either build your own world, or join friends in theirs. Hell, its even possible to download a dedicated server program thingy. But we'd have to get Deadly hooked and convince him to get it installed on the server

I think it supports 8 people at a time. Not sure. I'd have to look.
Ok, I've rambled on enough.
Oh, and tell HeX to accept her copy of the game. I know she doesn't have any free time, but what little she does has this game will easily consume. Think WOW, but with no monthly subscription fee
