As the name suggests, stoneflies are typically found in stony rivers and streams, although some species occur on the shores of stony lakes and in ponds and marshes. Adults are more commonly found crawling amongst stones and vegetation on the bankside rather than in flight. They fold their wings flat over their bodies when at rest.
Stoneflies by David Pryce, published in Salmo Trutta 2005 pp 41 - 44, includes an introduction to the group, details of the life cycle and a calendar of when species are most likely to be seen in flight. The article has been made available by The Wild Trout Trust.
Stoneflies by David Pryce –PDF-File, 1.8 MB