Hi and welcome. That is a great goal you have, and buying a treadmill would definitely be a great investment, especially if it gets really cold outside in winters where you are.
Alternatively, I've heard that those Nike running shoes you can get with the sensor in the sole are great for running/jogging/walking outside as it keeps track of the same info as a treadmill and its actually even more accurate. you hook the nike sensor up to your ipod and it feeds the ipod the info from your shoes. its pretty cool i've used it a few times, but only on the treadmill cause my gym had a free trial of the gear. my friend has her own set though and says its great. probably cheaper than buying a treadmill too.
also you should try setting short term goals, like lose 10 lbs in 6 or 8 weeks, that way you'll have something to look forward too and you will have soem great motivation once you reach your mini goals to help you get to the ultimate weight you want. To lose the amount of weight you want I think you would need to do 30 min of intense cardio at least 3-4 days a week, and do weight training on two other days.
www.sparkpeople.com is a GREAT resource for starting out with weight training, and they have a lot of ideas of stuff to do without even using actual weights.
as for eating in, try to make a meal wher half the plate is veggies (i usually do salad and some kinda veg), 1/4 of the plate is meat, and the other 1/4 is starch (potato, brown rice, brown cous cous, etc).
pre made salads are fast, and potatoes are quick if you nuke them in the microwave. you could pre bake some chicken breasts and have them ready to reheat in the fridge too...
ok well i'm done blabbing!! hehe bye for now!