DIET DIET DIET DIET DIET! losing weight is ALL in what and how you eat. PERIOD. cardio isn't going to do a damn thing for you if you're eating like crap. cardio is a far cry from the foods you consume. if you're working on burning off fat, then you might want to look into a CKD diet. it's a high (good) fat, higher protein, no carb diet (less than 50g carbs daily). the GOOD fats won't stick to you, you'll burn them for energy. the protein is absolutely 100% necessary to build muscle. the carbs....you can live without them if you've got bodyfat to burn.
go here -
www.elitefitness.com
register, hit up the diet forum. if it asks during registration if someone referred you, put my user name in there, as i post whore, err, post, over there a lot. you'll get some of the best advice that you've ever heard over on that board. plenty of people with years of knowledge.
good luck!