VERY GOOD:
TERRYSMITH.NET's Doing Objects in VB.NET and C#: Construction and Demolition

VERY GOOD: 
Implementing Finalize and Dispose to Clean Up Unmanaged Resources (.NET Framework General Reference)

Using Objects that Encapsulate Resources (.NET Framework Developer's Guide)

Using C# and Managed Extensions for C++ Destructor Syntax (.NET Framework Developer's Guide)

Overriding the Finalize Method (.NET Framework Developer's Guide)

Finalize Methods and Destructors (.NET Framework Developer's Guide)

Cleaning Up Unmanaged Resources (.NET Framework Developer's Guide)

Implementing a Dispose Method (.NET Framework Developer's Guide)

Forcing a Garbage Collection (.NET Framework Developer's Guide)

CodeNotes for C# CS050014 - Advanced Garbage Collection

Automatic Memory Management in the Microsoft .NET Framework
     article by Jeffrey Richter from the Nov 2000 issue of MSDN Magazine