A great, great site to go for advice is the www.fredmiranda.com forums. They have tons of info already available that you can search through and on top of that,

A great, great site to go for advice is the www.fredmiranda.com forums. They have tons of info already available that you can search through and on top of that, their buy/sell forum for used gear is highly reputable and you can save 20% off new prices for great, clean and high quality lenses. Hope this helps! Good luck and good shooting!