Today's mission: Getting inside E3 without actually being there.

The key to making successful, educated investing decisions is to act like an owner. This means understanding the companies you own and the industries they're in, as well as keeping tabs on competitors. As David and Tom Gardner suggest in The Motley Fool Investment Guide, trade magazines are great for this.

Last week, for example, was the video game industry's Electronic Entertainment Expo (E3). In case you didn't know, E3 is huge both for gamers and investors, as game developers shed light on what's going to be big in the all-important holiday season. The event is so pivotal that even before this year's E3 began, Sony (NYSE:SNE) announced its PlayStation 2 price cut, while Electronic Arts (NASDAQ:ERTS) said that it had agreed to bring its blockbuster lineup to Microsoft's (NASDAQ:MSFT) Xbox Live!

Unfortunately, most of us couldn't be there. So how do we avoid getting left out?

I subscribe to a number of video game magazines, including PSM (an independent magazine dedicated to Sony's PlayStation platforms) and longtime favorite Electronic Gaming Monthly (EGM). Unfortunately, those only reach my mailbox once a month.

For immediacy, I turn to

There you'll find hands-on impressions of some of the year's big games, including EA's Madden 2005, Activision's (NASDAQ:ATVI) Tony Hawk Underground 2, and Microsoft's surefire mega-blockbuster Halo 2 for the Xbox -- Mr. Softy's answer to PS2-exclusive games like Gran Turismo 4 and Konami's (NYSE:KNM) Metal Gear Solid 3.

Of course, there are also updated movies, pictures, and impressions from Sony and Konami's E3 presentations of their respective holiday super hits. Of particular interest to shareholders of upstart Acclaim (NASDAQ:AKLM) is an E3 coverage update to upcoming hopeful Juiced.

For Nintendo GameCube owners, IGN has movies from Nintendo's Metroid Prime 2 and Capcom's GC-exclusive Resident Evil 4. And once you get past the million pictures of E3 models (apparently E3 is a lot like an import car show), you'll find glimpses of Take-Two Interactive's (NASDAQ:TTWO) Grand Theft Auto: San Andreas.

There's a lot more, but you get the point. Active investing isn't about trading stocks on a daily basis so much as scouring for information, behaving as if you own the business (because you do), and making sure any decision you make is an educated one. And trade magazines, particularly those available on the Internet, are a great way to gain the understanding necessary to act like an owner.

One last suggestion: Check out GameMaker's E3 Notes on the Computer and Video Gamers discussion board.

David Gardner likes games, but he doesn't play around. Electronic Arts and Activision are both top picks in Motley Fool Stock Advisor. Take afree trial.

Fool contributor Jeff Hwang owns shares of Electronic Arts, as well as prequels to all of the games mentioned above.