Usually, reviews as soon as possible is nice, but otherwise you, I and (occasionally Ben) will work out a schedule. Under what we had with Sabre for a bit, it was two weeks.
Writing consists of 2,000 words split amongst 6 pages (Introduction, Story, Graphics/Sound, Gameplay/Control, System Requirements and a Conclusion). Weight of each section isn't particularly relevant, so long as it's balanced enough, and they're all filled out with what's needed. Into each review, a very bare minimum (Read "May Cause Unhappy Webmaster") of 16 images is required. 25-30 is a better bet, so he can sprinkle them into paragraphs. Make sure to take photos of things you talk about in the review. FRAPS is excellent for this.
As to gaming talent, we'd expect you to be able to take on and beat most games, but failing that (Read "Crazy Developers And Stupidly Hard Sections"), occasional Cheating may be needed, but don't run through the game with it on, as it'll ruin the experience, and taint your review. Length of play is preferable to the end, so that you can report on the fullness, accuracy and satisfaction begotten by the storyline in itself.
Answers the questions?