There are many useful online resources available to writers and one that I frequently browse is the BBC Academy, which can be found here: http://www.bbc.co.uk/academy/journalism
There are lots of useful articles, and videos, containing useful tips for all writers, nit just journalists. For example, Allan Little’s video about the principles of good writing (http://www.bbc.co.uk/academy/journalism/skills/writing/article/art20130702112133594) is relevant to every writer, no matter what their genre. (He makes a strong argument as to why journalists should read poetry, for example.)
Anyone looking to brush up on their English Grammar should check out the following link: http://www.bbc.co.uk/academy/journalism/article/art20130702112133612 and for some guidance on spelling and punctuation, check out http://www.bbc.co.uk/academy/journalism/news-style-guide/article/art20130702112133530
What you might find interesting in the BBC’s Style Guide (http://www.bbc.co.uk/academy/journalism/news-style-guide), which gives you the lowdown on when they prefer to use digits for numbers and when they’s rather spell them in full.
Of course, it’s worth remembering that the BBC Style Guide applies only to BBC journalists. If you’re writing an article for another publication they may prefer a different style guide. But it makes interesting reading, because it’s a useful indication as to the sorts of things we need to be thinking about when writing.
As writers we’re always learning, and this is one resource that has many answers.