What is the best way to write and also distribute a press release?

If you are a good writer, you can just master these: WHAT, WHEN, WHY, WHERE, AND HOW. Or simply find good writers on freelancer.com, debrief them about what you want the press release for, pay them. They go to the PRwire website and simply  create an account and post your press release into the relevant category. You will reach as many newsrooms as possible.

Depends on the journalist to whom you're sending it:

Here in the UK at least, local newspapers are understaffed so write it for them as much as possible. They want neutrality, facts and an interesting angle - if you make it too 'salesy' they won't use it and will avoid you in future. Or they will try to sell you some advertising space. 

Nationals and TV will want to write their own so give them facts and figures (bullet points help), the key messages, an interesting hook and your contact details. Tell them why they should be interested, always bringing it back to their audience. 

All will want accompanying images (jpeg,1MB,300dpi), further contact details and a few quotes, citing full name and job title. 

Always call first to let them know you're sending it, and then again afterwards to check if it's being picked up. 

And a last tip, take off your corporate hat. Unless it's a business title, most news outlets don't much care if you've appointed a new HR manager, are saving the environment by recycling plastic cups in the staff kitchen, have just done a deal with a new groundskeeping contractor etc. If you have lots of mundane news that your company thinks is important but you don't, save it up for a 'round-up' press release on a slow news day!