As ever this is not an instructional manual, just a few tips:
First, whatever the scale of your press release distribution and no matter how big or small your story, always put it on PRWeb. They will get it to many places you don’t know about, your story will be used by all sorts of people looking for content and you will get a quick web presence. For US$120 a pop it is a no-brainer, but don’t rely on it as your sole distribution method.
If you don’t have a PR company and don’t have any lists then you could go to the nice Russians at SoftPressRelease who will distribute your release to over 1,000 games journalists worldwide for $125. You will get a fair number bounce back from dead email addresses but this is inevitable with any list.
If you are dubious about your press release writing capabilities then both of the above have an economic release writing service.
There is another essential distribution mechanism and that is Gamespress, which is very widely used by games journalists and is free to use.
Using the above three mechanisms you can get very good distribution of a press release (especially in the English-speaking world) cheaply and quickly.
The only media you must always, always, send stuff directly to are the trade magazines. These are a lot more important than the consumer magazines in many ways. These three are online so can get your story out to the key audience very quickly: Gamasutra, MCV and Gamesindustry.biz.
If you have any useful tips or other comments on this then please post them here.