Ok, just remember there are hundreds of thousands of other websites that are going to try to disprove what you are saying. Try to make yours sound as informed and realiable as possible. Give it something extra. Remember, you're competing with the all knowing Yahoo!Answers, which is always right, you know
. Try bringing in other people, contact others who know
what they're doing, like OFL. There are some other VERY helpful people on other forums as well. I know on Aquarium Advice that Severum Mama is one of the most knowledgeable people on there. Ask them to write an article, or perhaps ask them some questions for an article that you'll write. Give great links to other places, plantedtank.net and seriouslyfish.com are AMAZING places to receive information on fish, the latter more so than the former.
These are, once again, things that I have picked up through the course of blogging, that I really think that you should know. It'll help you get that leg up on Wikipedia.
Oh, and don't use Google Images for pictures, those are usually copyrighted and you probably don't want to (possibly) get sued. Try asking others for pictures or take some pictures yourself.