3 cats and moving: Should we fly? What should I expect from taking cats on a plane?

Me and my roommate have 3 cats. All three are full grown but are very small (rescues that were malnourished at baby stages) two of them weigh about 7-9 pounds and one only weighs 3 pounds (poor thing is so tiny). Were moving from Socal to norcal and are wondering what to do about transporting them. The flight is only an hour, so were wondering about doing that--how hard would this be with two pengers? Im not quite sure how theyll travel. What should i expect having to take the cats on the plane? Sedation yes/ no? carry on yes/no?