Disclaimer: I haven't read your series, so it's quite possible there are some references that I'm missing in my general critique. That said, it's also possible that I'll be giving the opinion of a potentially new reader, someone who isn't well-versed in the universe's nuances.
I'm going to echo shadowphoenix's thought on the login page location. A general web design rule of thumb is to put the most important visuals/images in the top left corner, since that's where a visitor's eyes will go first. Since the banner isn't anything huge (the small graphic reads more like a logo than anything that would tell me about the site's content), my eyes scanned below it to see the login page. It makes me think that the primary importance of the site is to be a communication network (forums/blogs/etc) instead of a fiction site. I would suggest putting the "Engine Creations" section above the 'log-in' area. That'll help readers understand that the site's for fiction, as well as be able to find it with a lot less effort.
Perhaps having a strong central image in the banner or on the page would help to draw the eye. As things currently stand, the most vibrant images are the ads on the page -- which are great for the advertisors (since they catch my eye), but not so great for your site. The problem with your current image/logo is that it blends into the background. It doesn't stand out, and it doesn't really tell me much about the style of fiction you hope to be hosting. Graphics aren't terribly hard to come by, even if you have to hire someone (I know people who do banner graphics and the like for $10, etc). The benefit of graphics, however, is immense -- they draw the eye, they help set the mood of the site, and they can betray in a simple image the content that a reader will find.
As for your 'Welcome' sticky, I would put the actual explanation of the content above the "New Readers, start here" section (as a side note, don't randomly capitalize the word 'readers' in that sentence). You want your readers to be able to figure out what the site is about as easily as possible. Another web design rule is to realize that visitors generally spend five seconds on a website before deciding to stay or move on. In that sense, a single sentence could very well make or break a potential reader. It's also more intuitive that way -- new readers are more likely to want to start after they know what they'll be reading.
Also, I don't know how attached you are to "Engines of Creation" as the main site name, but I'm not really fond of it. It doesn't tell me much about your site, your intent, or your genres -- it actually makes me think of applied arts more than fiction. ;
The final thing is the color scheme. That sort of icy blue seems very detached -- blue, in general, is a cool color, which can lead to a bit of a 'meh' feeling from visitors. Perhaps, if those colors are of particular significance (or if you can't adjust them due to the colors being provided by a template), you can keep them, but I wouldn't. Instead, I would choose colors that evoke the feel of your series.
Hope that helps, and isn't too overwhelming. ^^