I have several sets of plans from  Stevenson Projects and they are all the same format.  They are 1 or 2 large sheets that are folded.  The boats are typically single chine with slightly rockered flat bottoms with full length keels. The Circle Skipjack design is a 12' dailsailer with a lanteen rig (think sunfish).  It has a decent size cockpit and seating on the rear deck.  Tiller steering, drop in daggerboard and short bowsprit with forestay to support the mast.  Many have also been built with gaff rigs and jibs to mimic the boats larger sibling the Weekender. 

The plans sheets, pictured below, give dimensions for all the major parts including bottom, bulkheads, deck.  Rough sizes for the sides are given and there is some adjusting to fit during the building process, which also goes for the daggerboard / mast step assembly.   The plans give great instructions especially for those that do not have much experience in boatbuilding, using plain langauge and not overdoing it with nautical terms.  Much of the hardware in the plans is also standard hardware store issue, such as barrell bolts for attaching the rudder instead of pintles and gudgeons and 6 mil plastic for sails.  Additionally references to tools like the old "yankee type push screw drivers" as opposed to the battery operated That being said many an experience builder has built Stevenson's boats and have substitued "saltier" rigging.   I would say these are fun designs, but in some respect a little outdate.  That being said this designer has just posted a new 14' version of this boat on their website and plans should be available late spring, so I will anxious to see their updates.  These are solid fun boats to build and throughout the month of March I will post links to projects.