Studying clusters with Planck

We use mock Sunyaev-Zel'dovich effect (SZE) maps to investigate how well the Planck mission might find and characterize clusters of galaxies. We discuss different combinations of frequency maps and different methods for identifying cluster candidates. The resulting catalogues are not complete even for relatively high mass thresholds, but the full sky nature of the mission ensures a large sample of massive, high-z clusters which will be ideal for many studies. We make a preliminary attempt to identify the X-ray, optical and weak lensing properties of the Planck sample.