You just hit the jackpot. You're right in between the two best (in my opinion) hiking spots in Southern California: The San Bernardino Mountains to your north and the San Jacinto Mountains to your south.
If I may make a recommendation, go to your local bookstore or Amazon and look for John Robinson's, "Trails of the San Bernardinos," which I think is a really good trail guide for the area.
http://www.amazon.com/San-Bernardino-Mo ... 0899974090 This is just a suggestion on my part; Jerry Schad and John McKinney both have good reputations as authors of trail guides. I don't know that they have a book that focuses specifically on the San Bernardinos and San Jacintos, but you could browse through whatever they have at your local book store.
You could also just go to the Palm Springs Aerial Tramway any weekend, ride the tram up (a bit pricey but worth it), and then go to the book store that is run by volunteer rangers. They'll have some decent maps and things. You can take some really nice hikes right from the top of the tram. Note:
Right now there's a lot of snow up there.
Welcome to the board and to some great hiking country.