One way that I decide is by checking out the picture forums. Then I reference those pictures to the tank specification forums and bam!
It gives you a really good idead of the tank you want.
My opinion is that you can't become an expert over night, nore should you want to. The whole point to this hobby is the adventure we all share in learning from it. Everyone here has made mistakes and you will too, but that is what makes the hobby what it is. Good luck with your set up and welcome to the board!
Danny