John Welsford's designs for dinghies
and small open sailing vessels are great. If you visit the Duckworks website you will see links to all facets of design and building of small boats.
I am not affiliated with either Welsford or Duckworks but recommend them because the first boat I ever built (four years ago) was Welsford's "Tender Behind" model. It was easy and relatively inexpensive and is a gret little boat for towing or rowing or sailing.