For me, diet is first on the list. You can train like a champ, but if you are not eating right, your results will not be as good as if you had the right diet.
For loosing fat, first, cut all refined sugars (sodas, juices, candy, etc..)
Second, cut down on your carbs (limited bread intake, find some rye bread. Definately loose the bagels and butter thing, get lots of green veggies)
Third, log all your meals, I mean every single thing you eat and try to keep count of protein, fat, carb and total calories. At the end of a week, look at your eating habits and cut where appropriate. Post what you typically eat in a day and people here can then help you fine tune your diet.
Fourth, keep reading. There is a wealth of information on these boards, and it takes a while to catch on to the lingo and concepts that people recommend.
Fifth, ask questions. People here are very friendly and helpful. Don't be afraid to ask questions, that's the only way you'll learn.
I am currently on a cutting (fat loosing) diet, and this is what I put together with the help of everyone here.
Current body weight, multiply by 11, that is my total amount of calories per day. I then do a 50/30/20 P/F/C, which means that I take in 50% of my calories from protein, 30% from fat and 20% from carbs. I choose what I eat carfully, I stopped eating fast food, and basically cook every thing I eat, the only way I can really control the diet. I log every single meal, weigh my self once a week and change things in my diet according to the progress (or lack of). I know it seems like pain in the ass to do all these things, but it's the best way for me to keep motivated and concentrated on my goals.
I also started out doing tons of cardio, about 45 mins. 4 days a week, but since I started with the diet, I work out 3 days a week, I do 10 mins. cardio pre workout and 10 mins cardio post work out (not much at all) and i have lost over 15 lbs in about a month and have developed some muscle. Too much cardio can hinder you from building/retaining muscle.
Hope this helps, good luck.