Anyone recommend a specific sound design program or certificate or anything like that, that will help me prepare for video game sound design?
I don't know of any certificate that would really help in being prepared for Game Sound Design. What does matter is a complete knowledge on the topic of audio in general, and a passion for non linear sound design.
You need to be educated and experienced in microphone techniques and recording, in hardware and software routing and processing, in acoustics and computer science as well.
I would be skeptical of any educational program that was based around sound design as a topic, before the world of sound and production were addressed correctly first, unless it was a graduate level program. At the beginning, you should find something that teaches every aspect of sound production, and focus your practice and skills towards Game Sound along the way.
A good deal of indy level game sound will go along way. There is nothing to replace actually doing and practicing the craft. Get on a mod team, and put your heart and soul into the process. Make your sound design unique and original, and practice implementation as often as possible.
Good audio schools are very expensive, and do not guarantee you a job in the industry. However, the amount of information that you need to be a solid audio producer often goes beyond what you could possibly teach yourself.
Have you taken a shot at any production yet?
if you want to explore the technical aspect of game audio and make sure this is for you, grab a copy of Fmod or Wwise, get to know the concepts and start thinking. Of course, passion for games is a must, but game sound is as much about sound as it is about hacking. You can expect to work with other content people but also programmers and they have their own ways... mindset is not only important but gets a bit more specific on these projects... I agree with Ryan, it's entirely possible to be self-taught, but education can give you flying start and hook you up re work experience and such...
They've got some good classes at Berklee with Jeanine Cowan teaching. Besides game sound, you should have a strong background in audio in general, music theory, psychoacoustics, etc. I agree with others that playing games and listening is crucial to your preparation, but also listening to your real world and understanding what makes your own acoustic universe function. Then learning the technical aspects will give you tools to do it yourself. I'm giving a free intro webinar Aug. 24 that will include a lot of this, not specifically for games but for all audiovisual. Check it out SoundDesignForPros.com.
Get on a game mod, or swap out the sounds of an existing game (I still use Doom editors for this, even though Doom's 16 years old.) It really helps to hear your sounds in a game environment, to see if they all mesh well together. I'm not sure about WWise, but FMOD has in-game emulation, but I feel it doesn't do it justice until you can experience it as a player.