I have reasently bought some heart pine 4x6 beams I will be ripping to 3/4 in a bandsaw mill.. I am going to be making this my floor in my home I am rebuilding.. the house was conventional and I will be going back with concrete.. I will not be doing t&g.. they will be square cut.. I planned on biscuit joining the boards together but not sure.. is it best to lay the flooring directly on the concrete.. any advice will be appreciated.. thanks in advance

First make sure that your slab is flat to within a quarter inch in ten feet by grinding down high spots and building up low areas with latex fortified cement or self leveling floor patch.
There are product that seal the slab first or you can use a combination seal and glue. These are sold where hardwood floors are sold. Follow directions on the bucket.
You will probably need to weight the planks down with some type of weight after the boards have been positioned in the glue. Back kerfing will help with contact.
Set a skilsaw blade to half the depth of the plank and cut across the boards where they don't have contact with the floor before you set them into the glue.