Help with workout!!
The elliptical is a great machine it works your whole body. Most have levels from 1-10, so start out low. Try to up your level and work up to 30 minutes on it. Also your gym has a trainer there to help members. Get with him and talk about what you want to do with your fitness. He can help you alot.
I have problems with my sciatic nerve and I do the elliptical for 30 minutes three times a week.
I think it's important to up your level of exercise slowly to get the best benefit.
Hey! Glad to hear that you're starting an exercise regimen. A key point to losing fat is resistance training. Another key point is aerobic exercise training (which you are doing with the walking). The final piece of the puzzle is the largest and hardest to change...your behaviors. You have already started conquering two of the pieces to the entire weight loss puzzle, and that is a very important step.
What you personally have to do though is figure out exactly what it is you like to do. I recommend obtaining a day pass (not sure of the cost, if any) at a local YMCA or health club or gym and try out different exercises (aerobics, yoga, etc.) and see if you enjoy them. There are literally thousands of different exercises that will increase your fitness and help burn fat...the key is to find something you enjoy. If you find something you enjoy, the more likely you are to stick with it and receive the most benefits from it.
I personally recommend that you, at least at first, increase your daily physical activity as a whole. This inclues taking the stairs instead of the elevator, gardening, etc. Remember the main goals of an exercise prescription: improve mood, quality of life, physical functioning, caloric burning, and weight loss.
One option that I highly recommend is the low-intensity lifestyle activity (i.e. gardening, taking the stairs instead of the elevator, parking further away from the building and walking more). This will increase your daily physical activity and promote calorie burning. This gears your body for exercise in the intial stages.
Another option is a non-weight bearing activity, such as swimming, water aerobics or stretching. These are great activities to increase fitness without as much strain on your joints. The walking on the treadmill is a great aerobic workout that is ideally suited to burn fat. Another weight bearing activity that I personally recommend at least trying is Taijiquan (T'ai Chi). It is a great moderate level aerobic exercise that is ideally suited to burn fat as well as help with many of the joint problems that accompany obesity.
You should probably start with a moderate level of physical activity for about 45 minutes 4-5 days per week. As time goes on and your fitness level increases, you will be able to increase your activity to about 30 minutes of moderate intensity (e.g. power walking) on most, if not all, days. Also remember that dietary changes are important and you want to eat enough carbohydrates (breads, cereals, pastas, etc.) to fuel your workout. Stick with unrefined complex carbs as well as fruits and veggies. Protein and fats (unsaturated fats are ideal) are the other legs of the diet equation. Hope that helped and I look forward to hearing about your progress! Good luck!