i dont know too much.. slice an onion, dip it in oil and rub it on the grill.. use the onion to lube the grill time to time?
marinate steaks with adobo.. or meat tenderizer. if you dont have that, reg salts fine and u can mix it with whatever else u got..
i couldnt tell u the times, id do it by sight.. it would depend on how hot the fire is burning i guess.
hopefully someone else's answer will help you more!
what i really love on steaks is a chimichurri sauce, if u can find the recipe online its somehting like garlic, onions, parsely, cilantro (i think,) with salt and vingerar or olive oil? it's somehting like that, and you use it as a dressing for when the steak's done..
i don't know the exact recipe but maybe you'll like to try it if you don't already know and love the stuff. it's common of argentinian or brazilian steaks/steakhouses.