How to Improve your Chess
The website chesstempo.com
is full of excellent resources to improve every aspect of your game. A few hours spent on the tactics trainer will pay dividends; you will notice the difference when you next play over the board.
To follow international tournaments theweekinchess.com
is first class. Playing through grandmaster games and, when broadcast, watching live video with commentary will lead to improvement.
There are some superb resources on youtube. Kingcrusher is my favourite commentator. This example of D.Byrne v Fischer
"The Game of the Century" is one of many examples.
To play online, chess.com
is one of the most popular sites and contains numerous resoures.