Wilson's highly readable "Uniprocessor Garbage Collection Techniques" is a far better overview: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.138.... You could write a decent GC with just the info in that paper.

It doesn't cover parallel or real-time garbage collection (which both get far more complicated); for those, you want Jones et. al's _The Garbage Collection Handbook_ (http://www.amazon.com/The-Garbage-Collection-Handbook-Manage...) and plenty of time to explore its bibliography. (His older book is also good, but doesn't cover those topics.)