Just get Kenny Erlebens thesis from http://www.diku.dk/forskning/image/publ ... leben.html
or order his book: Physics Based Animation.It's very good. Next to that, you can read Erin Catto's GDC publications at http://www.gphysics.com/
On Collision Detection, I can recommend Gino van den Bergen's recent book published by Elsevier "Collision Detection in interactive 3D environments", or his PhD Thesis "Collision detection in interactive 3D computer animation", which is for download
at Eindhoven University, in the Netherlands: http://www.win.tue.nl/lotgevallen/promoties.htm
or local cached copy here
. Also Christer Ericons book is good, see http://www.realtimecollisiondetection.net
. However, some good information on contact manifold generation, penetration depth and time of impact is important. Browse these forums for more info on these topics, or see the Bullet source code.
Also check out the mainloop in btDiscreteDynamicsWorld in the Bullet 2.1 Physics Library sources. That will hopefully be more clear then the ODE sources. Bullet's constraint solver approach is sequential impulses, which is equivalent to ODE's iterative quickstep solver (successive overrelaxation/Gauss Seidel).