I'm flying Orange Co. to Kona on Aloha Air just after Christmas. Haven't flown in years. Any tips? Flt. leaves at 8:45 am. How early should I get there? (I'll be dropped off.)

Also, any tips while on the Big Island? Staying at Waikoloa Beach resort. I like to snorkle.
Any warnings? Rip-offs?

Thanks!
Jeff