Welcome, maryellen! You've gotten a lot of good advice already...I have to agree with the tip to log every bite of food and sip of any drink that goes into your mouth. You will be amazed how quickly the calories add up!
To decide how many calories to eat, you can use a calculator like the one found here: Calories Per Day Calculator
or just Google for Calorie Calculators. To lose 1 lb per week, cut 500 calories per day from that number. To lose 2 lbs per week, cut 1,000 calories per day from that number.
Drink lots of water, eat as many whole, unprocessed foods as you can, and exercise on your eliptical and Wii as often as possible. The pounds WILL come off!
I also agree with the suggestion to find a group here on the forums based on how much you need to lose. It really helps being with like-minded people who know what you're going through!
Best of luck. =)