The resus council guidelines on peri-arrest arrhythmias.
A nice little resource discussing the causes of hypotension, not quite complete but very good.
Sooby Says: A little article designed for patients discussing the causes of bradycardia. It's very easy to read but remember to include the more medical causes too.
Sooby Says: This is a nice little article on the causes and identification of tachycardias. The only thing I would say is there aren't many ECG pictures, so remember to check how each pathology looks on a cardiac monitor.