Hopefully this link will take you there, lots of idea's and tips:
http://www.hgtv.com/hgtv/gl_design_water_features/article/0,1785,HGTV_3575_2644263,00.html
From complex to simple, this is a great on-line article.
A plethera of water garden ideas & maintenence tips
Great link! I think the one on the Garden Pond and Waterfall is the best resource for the rock work. What I've found is adding too many of one size of rock makes a pond or streambed look unnatural. The example shown has everything from pea gravel to large rocks, and it really works for a great natural looking water feature where the rocks don't look 'arranged.'
Great link. Thanks for sharing. :D