A simple weight lifting program you could start with would be something like:
Day 1: Legs (Monday)Squat or Leg press
Leg extensions
Leg curls
Calf raises
Day 2: Push (Wednesday)Bench press
Military press
Tricep extensions
Some ab exercise
Day 3: Pull (Friday)Deadlift
Row (bentover or cable)
Lat pulldown (or pullups)
Bicep curls
For all of these lifts, aim for doing a warm-up set or two followed by three sets of 8-12 repetitions per set. The first set should be pretty easy, the last set pretty hard, but start with some light easy weights until you get the form down. You can keep the same weight on each set or increase the weight each set. There are tons of more detailed programs you can follow if you'd like, but this will give you a good start for getting the form down and just getting comfortable with moving the weight and pushing yourself. If you're not an experienced lifter, get someone at the gym to show you the proper form for the Big 3 (squat, bench, deadlift). You can find animations of these and many other lifts at
http://www.exrx.net/Lists/Directory.html. Using machines for some or all of these lifts is fine, but you'll want to switch to primarily free weights (barbells and dumbells) at some point.
I know fuck-all about nutrition, but a few basic tips are:
(1) Generally you want to eat 4-6 smaller meals throughout the day rather than 1-2 big meals.
(2) Always eat breakfast, no matter what, get something in you before you start your day.
(3) Try to get most of your carbs from veggies, fruits, and whole grains.
(4) Try to get most of your protein from whole foods (chicken, turkey, lean beef, fish, dairy, tofu) rather than supplements.
(5) Nothing wrong with a little fat too (you need to eat some), but avoid saturated and trans-fats. Good sources of fat are things like olive oil, nuts, and peanut butter. Avoid animal fats by buying lean meats.
Losing weight is simple from a mathematical perspective: change in weight = calories in - calories out. So to lose weight, just burn more than you take in. A pound of fat is I think 3500 calories, so you lose one pound for every 3500 calorie deficit that you wring up. A dietician can help you with figuring out how many calories you should be eating and what your calorie deficit on a daily/weekly basis should be. In general you should avoid drastic daily deficits. A deficit of like -500 calories per day is just fine for most people seeking to lose weight while maintaining good health and body function.
It's a good idea to ingest 20-30 grams of protein shortly after lifting. You can get a protein powder supplement, or just drink a nice big glass of milk

Hope this helps! Good luck with achieving your goals.