There are many chessbooks/instructional videos on the market today.

 

Some of them good, some average whilst others are 'sleep inducing'. 

 

It's well worth remembering that it's not about how many chessbooks/dvds you have in your collection but how well you have assimilated their knowledge that counts.

 

Here is my list (updated regularly) on the best books which I have found beneficial to my chess progress and understanding.  I have ommited opening books/videos as obviously this is highly subjective to the choice of openings that you choose to play. Check out my posts regularly for reviews on books/chess dvds that I just finished.

 

Hopefully this will save you much grief in having to choose a good buy.