well, since you asked for 4 swds and I have no idea what that means, I can offer you a couple places.
I checked out SWDS http://swds.org/
but could not find any information about solar tracking.
" unique habitat for birds, bugs and other little creature...."
for what I know about solar tracking...first Dwyane over at Redrok invented the application of using 4 LED's as the sensors. it has been copied many times, so I would start there.
that site offers a non-arduino solution as it uses the sensors to move the motor.
the problem is that without the smarts, it has a few areas that it cannot handle. such as it will not follow with clouds and does not have either a night return or a flat setting to eliminate the effects of wind.
the guy is brilliant, but not great on web page design.
the other place is the guy who is brilliant with arduino code for the same application. not sure if he uses 4swds though.http://www.cerebralmeltdown.com/
this is a calculated postioner that uses your location on the planet, the alignment of the sun along with the rotation of the earth and will point the array at the sun. it does not use feedback so if your alignment is off, your tracking is off.
both are very viable technologies and the blending of the two would make a great final project. heck, you might be able to install one at SWDS !