Hi Nick congratulations on losing the 70lbs! Could you give us a few more details. How much do you want to lose in total and what is your height etc?
When you say you can Bike do you mean you have a Gym Bike or a real bike? If you have a Gym bike at home I would highly recommend HIIT (High intensity interval training) Wikipedia has a page about it although it has been changed and reduced since I last checked it and the Bike section is now gone.
http://en.wikipedia.org/wiki/High-in...erval_training
Basically off the top of my head there was study that showed that 60 mins of Bike HIIT ( 20 mins 3 times a week) produced the same fat burning results as almost 4 hours of aerobic level biking a week. Basically because the short bursts from HIIT raise the metabolic rate so your burning losts of calories at rest for almost 24 hours afterwards. So you get better results for doing less work!!
For example on a Gym bike you could cycle as fast as you can for 1 minute then pedal at a comfortible pace for 1 minute. Thats one cycle. Repeat this 9 more times and this will add up to 20 mins total. Do this 3 times a week. Years ago when I was carrying abit of extra weight round my belly I found HIIT far more effective for getting rid of body fat then traditional boring cardio stuff like an hour on the treadmill etc.
Regarding diet it would depend on how much you want to lose to be honest. I would recommend starting out by cutting out soft drinks, crisps and chocolate and replacing them with Fruit, nuts and healthy smoothies. Remember NEVER starve yourself. If you don't eat the body will hold on to fat for longer as it's unsure when you will eat again. Eating also stimulates the metabolism. Small meals thoughout the day are good for the metabolism rather then just 3 giants portions a day. Thats why healthy snacking is good for weight loss. For something more comphrehensive I would recommend buying a food book from Amazon.