How do I select the proper trailer tires and wheels?

I am building a trailer. I know what the tires need to support. But I have not found a straight forward chart that says these are what you need. Can some one please explain to me what all this lingo is about? Load Range, C, D, E, ST, Ply, 2, 3, 4 Ply?How do I select the proper trailer tires and wheels?
That is telling you what the tire can handle before it blows off of the wheel. you always want to overbuild the tires to the application on the trailer. you are better off sitting with a trailer builder he can get your questions answered for you in a face to face setting. Just tell him you are looking to buy a trailer and what it will be used for, then let him make recommendations.How do I select the proper trailer tires and wheels?
Load range is weight that can be safely transported over a given distance. c,d,e, might be speed indicators for tires (A is highest). PLy refers to number of belts of rubber or steel in tire.

I'd choose by the weight I was looking to carry and shape of cargo (if a boat vs. boxes, that is)

nada boats