I had huge success 2nd time around last year (1st sowing was a disaster - when I put the seeds straight into the ground), I grew all my parsnips in toilet roll tubes. Just cut them in half, fill with soil, but 2 seeds per tube. Once they get going remove the smaller plant. Then pop the whole tube and plant into well dug soil in the garden. This doesn't disturb the plant at all (which they hate), and you can evenly spread them out without the hassle of thinning them. The tube will rot away in a few weeks. Win win situation... not bad for a 1st time novice! The parsnips were massive.