The goal of Oasis is to be a positive site. That extends to the way we treat one another on the site, as well as informing everything we do, including reviews.
Now, that doesn't mean we are going to like everything we review, of course. But I think it is important to find a way to avoid being malicious. I'd rather see us be constructive and nurturing, than slam people.
Similar to netiquette, reviews should explain YOUR reaction to the book. The book itself is what the author intended, so there's no such thing as what it should have been, other than what it is. So, "I related more to the story between Ted and Harry, and would have liked more of that," is better than, "The author kept going on and on about the stupid teacher, when he clearly wasn't interesting to anyone reading the book."
Another rule of thumb, and often a tricky one, is how to convey what the book is about, without giving a point-by-point breakdown of the plot. If you've read any of the books I've reviewed on Oasis, hopefully that comes across. It is easy to just say this happens, then this happens, etc. You have to tell people what they're in for, but somehow save the best moments for them to discover for themselves. And, adding SPOILER ALERT is just the lazy way out, so skip that entirely. As soon as you have an instinct to write that, consider it a cue that you're giving away too much.
The other thing is to consider is what the book is. When I read young adult books, I review them differently than when I read "adult" books, because they are written in a specific way for a specific audience. For instance, they generally focus on one major story, rather than four stories going on at once. But since that is part of the way those books work, it would be wrong to ding them on it. Similarly, if I were to review a horror movie as having less depth than The Departed, it would also be dumb. If Pat's book "Orphan's Quest" is fantasy, my review saying "elves don't really exist, so why am I reading about them as though they do" would miss the point of the audience for the book entirely.
The hardest part of writing reviews is when you have to write something negative, but I do believe in putting it out there, because artists need feedback to see what areas they can improve on. I'm writing a novel right now, too, and I am very much in my own world with it. So, reviews are a way to gauge where you need improvement for future books. But, anything like can be positioned constructively. I tried to do that with the Kate Clinton DVD review, although it's questionable whether saying everything was done flawlessly except her ability to make me laugh is constructive to a comic. But I didn't slam her personally (I would hope).
So, when giving the overall view of a book, try to give people some way to know what they're in for, with as little detail as possible. A lot of times, people like "Hollywood pitch" talk to describe movies and music. A new band is "Nine Inch Nails meets the Beatles," whereas I describe my book as "Weight Watchers meets Fight Club." Pat's book (which I haven't read) could be a "gay Lord of the Rings" or somesuch. It's somewhat dismissive to use this shorthand, but it's really pervasive, and often lets me know what I'm in for if I decide to check something out.
I think of the people who read a review as already debating whether they want that product, or assume they are open to it. So, there is a generalized assumption that the audience is "on board." So, write from that angle. If you're looking for a book that provides blahblahblah, yadayadayada, and more blahblahlblah, you won't be disappointed with [book title here.]
As far as length, there are no real rules. Just a few paragraphs, 8-10. I don't use long paragraphs, though, since shorter paragraphs are easier to read online. Just set it up, tell people what you like or don't like about it, given the site, we do focus on the gay element and what about that interested you, or not. What journey did the book take you on. But always think of it as a movie, what parts would you be pissed off about if your friend told you in advance, and ruining your experience because you knew what was coming?
It's also OK to personalize it. Hell, I always write as much about me as what I'm reviewing. But that contextualizes the review. If we know you're a LOTR fan, and loving a fantasy book, then that's a good tip-off as to your background and tastes. Nothing wrong with it sounding like half-journal entry, half-review. Oasis is a personal site, no need to switch hats entirely just because this is some "formal" writing. Have fun with it.
As for process, once reviews are written, we'll come up with a way to give them a nice edit or polish before posting them to the site. They will be written in proper English, with paragraph breaks, no netspeak or IM lingo. But beyond that, my goal is to make this be your review, as much as possible.