Giles has posted a link to a tremendous bit of writing advice by Dr Lucy Rogers.
The only point I'd quibble with is this one:
"Aim for the shortest sentence possible. Long sentences are hard to read and understand. A sentence of seven words is easy. Sentences longer than 29 words are hard going."
Mostly short sentences yes. But, occasionally, chuck something longer in there to break up the rhythm.
Like this:
By Gary Provost. Though I'm not sure who added the colour. Maybe here. And I'm not sure why the reader has to be 'him'.