Yep, that's the one, great.
Choose it, then you'll be given those three fields in the options bar. Following the exact instructions of your site, you'll enter "850px" in the width field, and "1100px" in the height field. Make sure you include the "px" part, this is very important. Leave the resolution field blank.
Once you've entered those values, show me another screenshot.
Layers & Masks. Sharpening won't make a lick of sense if you don't have the basic knowledge that L&M gives you.
Well, that varies for everyone. For some people it's only a week before they're ready for the Levels Class. Other people take several weeks, or even months. It all depends on how much you flood me with photos.