We are at the same stage: DS is currently in Year 5 and for Lincolnshire the tests will be held in September 2010. I emailed the schools we are considering through their own websites and asked for information. I was either sent the registration information or told it would be available at the school's open evening. I was surprised at how different the registration dates were: one was end of May (i.e by last Friday) the other wasn't until early September. I'm not sure how strictly they would hold to these dates but think it would be sensible to enquire sooner rather than later.