Ok,so I think what you're asking is;do you have the right rack,and what tires to use?

For the rack,we need pics of your bike. For tires,MTB'rs usually get longer life out of their tires than street riders because they're not wearing them down on concrete and asphalt. For the street you'll want 'slicks'(motorcycle-style tread,not offroad knobs) with some kind of puncture protection. Just about every manufacturer makes street tires for MTB's,it's just a matter of what you want to spend. What's your budget?