Realistic weight loss plan for the summer?

I am 5'8 and around 165-170 lbs and I really want to slim down a lot and get more buff during the summer. I have been going to the gym with my brother every morning as we do upper body one day and alternate with legs the other and so on. After lifting or using machines for legs I run the elliptical for around 10 minutes which burns around 150-200 calories. I've been going for a week and I see a little progress. So what's realistic for me, could I be skinny by the end of summer? How many calories should I consume a day to stay healthy? I have cut down on fast food drastically and am not drinking soda at all. Should I take body pictures every week to see progress? I have no idea where to check body fat %, as my gym does not offer it either. I've been eating chicken breast in a little seasoning and bbq sauce pan frying it with no oil/ butter etc. What else should I eat? I don't like veggies much =/