i set up a store put items in the store name it then hit open store but then its says you must have selected items for trading! what gives?

Make sure you are level 10.
Make sure you have reseted your pets skills.
Make sure you gave me karma.

Also make sure that you're not trying to sell anything that's equipped or any equipment that has been sealed from a red-named death in PvP.

You know what, I think it's about time I made a checklist for this issue and stickied it.