HyperRev catalogs are like a bigass parts catalogue for the specific model of car. We use em at work to identify parts on cars we buy, and also they're a great way to find prices of items quickly and contact details of specialist stores.
Option and Option2 are sorta like car mags with new product reviews, DIY guides, tuner cars... Option is sorta like Wheels, and Option2 is sorta like HPI... just... umm better.
Drift Heaven (DoriTen) is probably best described as the Japanese Driftbattle magazine... just... ummm better (notice a trend)
Club Skyline is a magazine that deals specifically with Skylines (GTR's, oldschool and family variants). Its only up to issue 21, its been running for a couple of years now. Its got great coverage on the newest stuff for Skylines, club meetings in japan, and other funky stuff.
There's also VIPCar, which deals with Celsior's, Aristo's, Crown's, President's, Q45's, Gloria's etc in all manner of VIP-ness (and some euro barges).
Only problem is that they're all in Japanese, so you've gotta have japanese coworkers that you can bug every 5 mins to ask em what something says, or be able to read it yourself (or have a japanese partner).