Using a Script
First, rez or create an item. You can rez an item by dragging it out of your inventory into the world, or create a new prim by right-clicking (option clicking on a Mac) and choosing "create".
You will need to have modify permissions to add a script to an item, so create a new prim if you're not sure. You can always transfer the script later!
Next, right click (or option click) on the object and choose "edit". Switch to the "content" tab on the far right.
Create a new script by clicking on the "New Script" button. I suggest that you right click and choose "rename" to name your script something more descriptive, so that you can find it later!
Double click on the script to open it. The default script is designed to say hello to you, but not much else. Delete it, by highlighting all of the text and hitting the delete key.
Next, return to the autoscript web page and generate your script. Copy it to the clipboard if you haven't done so already.
Paste your script into the empty script window. Click the "save" button on the bottom right of the window to save it.
You should see a message below the code that says, "Compile successful, saving...", and below that, "Save complete." Your script will now be running!
Please report any broken scripts or scripts that don't behave the way that you expect them to by IMing Ann Enigma. If there is some additional functionality that you would like to see, please let me know.
Have fun scripting!