You weigh about the same as me (I'm 5'11"), I'm going to the gym 6 days a week. I have Fridays off to do whatever I want to do (not going to the gym) and it has seemed to work out well so far. I think that it is good that you are going to the gym (or getting some sort of activity 5 days a week). It will not only speed weight loss, but if it's something you like doing, it won't seem as hard.
Biking is good cardio if you keep your heart rate in the optimal range. Otherwise what has worked for me is the eliptical at the gym. Right now the only thing that I can suggest to you is drinking a lot of water. It seems to help shed pounds, and also it somewhat helps with hunger.
Joined fitday 6-18-2011 249 lbs
6-25-2011- 237 lbs
Next weigh in: 7-16-2011
Goal for now 200
Goal later on 180