How to improve Writing Skills

Hello everyone,
I have a quick question for those that know how to write well, and to communicate your mind effectively. I would like to know, how to learn how to write appropriately, and effectively. I notice that whenever I sit down to write, it takes me hours to do it. I also have a problem to write in a organized manner, however if anyone of you might have any input on my questions, it would be appreciated. Thanks for your time..
doublej

Thanks Mister, I read over the site that you refered, it seemed to help understand things better. I'll try googling and find more useful links as well. Thanks again