Thoughts of spring migrants

I have never usaully tried to apply much science to birdwatching, or if I have it's been for planning specific trips to Spurn etc. So I was looking through Bird guides looking for when Spring migrants had been seen in and around Doncaster, in particular migrating Gulls and Terns. I think I will have to make some effort to stop off at Lakeside...Last autumn I managed to find a Black Tern, on the lake. It would be nice to find another Black Tern going the other way and may be a Little Gull. We shall have to wait and see.