How to check a beam properly with Inventor 2012?

I have been trying to figure out beam analasis on Inventor. First I am not sure what the correct inputs should be in forces. Also not sure how to properly constrain for desired analasis. EXAMPLE: I have a S15x42.9 beam that is 29 feet long. I want to distribute a total load on top face of 2500 lbs in 5 equal 500lb loads staying about 24 inches from both ends. And then decide if i need more beam or less to hold load. Not sure how to input the load for analasis or how to convert it and what units. Can someone if they have time to demonstrate the use of inventor to check a beam for load bearing capacity in a tutorial or a link to such information. Where and what type constaints, explanation of load force units and their conversions from known loads in pounds. Anyways, that's what I need. I know this is probably a big task, but I need to know and I haven't had any luck finding what I need on the internet as of yet. Thank you all for looking.