There's a free template linked from my sig... use that for some help with formatting and press release writing tips. I also have several articles with tips at http://publicrelations.bizammo.com As for submission, since you're working with a somewhat specific niche (not only the UK market, but technology as well), you'll be best off submitting directly to a few UK tech publications (online and offline), and using a UK newswire or service if the news has regional relevance, but not too much potential to be newsworthy internationally... depends on your actual news.
If you submit manually like I mentioned, then no, you don't pay. You also wouldn't pay to submit to a bureau with a real newswire like AP, or using free distribution sites. You only pay if you choose to use services that charge you.
That depends entirely on your niche, whether you have a strong and legitimate news angle, and what your goals are for the press release (whether you want real media coverage or not).