Do you know how - meaning do you have real-time hands-on training and experience with both walking in crampons and self arrest? How about moving as part of a rope team and crevasse crossing/rescue techniques? If not, GO GET SOME. Mid-climb on Mt Hood is not the place to suddenly have to learn. Books teach theory and illustrate technique; they won't give you the practical skills you will need.
Your reaction to a fall has to be automatic; you won't have time to think about what the book said when one occurs. You have only seconds to self-arrest (how many depends on the slope of the runout) or you'll be going too fast to stop.
Like snowshoes, walking in crampons requires a subtle change in the way you move your feet as you go forward. Catching a crampon point in your pants leg is a good way to fall. If you're on a rope team, your fall could take the others with you. Also, use 10-point crampons only; 12 pointers are for ice climbing and require an even more critical walking method to avoid jabbing your foremost Achilles tendon with the front points of the following foot.
Unless your friends have a lot of experience mountaineering and know the approaches well on Hood, you're better off hiring a guide.
And please, sign in and out at the climber's registry at the ski building by Timberline Lodge and carry a locator beacon. Mt Hood SAR and the Hood River Sheriff's SAR units will thank you, and it could save your life.
Oh yes, be prepared to start your climb about 2 am so as to be down before the snow softens mid-morning.
Rent the plastic boots as well. You will want and need the insulation, firm support, and traction they and full-on crampons can provide. Trail runners and their associated crampons might be fine for snow travel but IMO, Hood's glaciers and ice fields are no place for such things.