Speaking of free books... Below are the list of free ebooks that I recommend reading/downloading for this month. I personally love Karl Seguin's book and giving it 5 out 5 stars is actually an understatement if you ask me. :)
Karl Seguin's Foundation Of Programming: Building Better Software rocks so much I recommended it to everyone I know. This 79 page book is pack with a hearty bowl of software development knowledge that would teach you about the principles of development that you should have known way before you started coding that nightmarish system.
Red Gate's Dissecting SQL Server Execution Plan is a must read for anyone who deals with data on a daily basis. It talks about how to optimize your querries and understand whats causing your querries to sleep on you while being executed.
InfoQ's Domain Driven Design Quickly is a quickly-readable summary and introduction to the fundamentals of DDD that tries to summarizes Eric Evans' book as well as Jimmy Nilsson's Applying Domain Driven Design and various other sources. The book gives you hints and tips about DDD as well as ideas on how to start DDD in your own projects.
Minh T. Nguyen's Visual Studio.NET Tips & Tricks is a must read for all developers who use Visual Studio. Enuff said!
So what are you waiting for? Download and read 'em now!