Cook the pasta in boiling salted water until al dente - the time needed will depend on whether the pasta is dried or freshly made. Take care not to put too much pasta in the pan at once since it may take some time for the water to return to the boil and the pasta may stick together.
Drain and refresh under cold running water for a moment then transfer to a bowl of cold water enriched with a tablespoon of olive oil [this helps to keep the sheets separate until they are needed]. Drain again and use to assemble baked lasagne or to roll into cannelloni.