When you're trying to track progress, consider the following measures:
1) Do you feel better -- mentally, physically, emotionally, spiritually -- exercise released endorphins, clean diet clears out shit that can bog down your body -- more energy, things are running cleaner & more efficiently, you sleep better, etc.
2) How do your clothes fit? Tighter? Looser? in different spots? Different? -- e.g. when I start dieting my jeans are baggy in the waist & tight in the quads. That's just showing you where teh squishy bodyfat is going away and the muscle is starting to show itself. You know how your clothes fit you and since the clothes size doesnt' change and its not a subjective thing - your favorite jeans are either tight or loose. If your "fat clothes" are getting looser, time to see how the "skinny clothes" fit. If stuff is still a bit tight, dont get discouraged but rather ENVISION how close you are and focus back on the gym.
3) Bodyfat measure -- 7 pt or higher bodyfat measure w/ calipers. The final number is not so important (because the number itself can make you freak out and additionally, manual skinfold measures are ballpark - they are inaccurate to a couple % bf), but the RELATIVE CHANGES between each week's (or whatever interval) measure gives you an idea of how your body composition (fat , muscle) is changing. But remember that it is just a data point - its not a live or die thing to reach 13% bf or whatever. Its just a measure in time.
4) The scale -- its still just a data point. It measures the combination of bone, bodyfat, muscle mass & water. The water is usualy the biggest fluctuatoin - very easy to see 3-10 lb swings durign "that time of the month", after a big carb load, whatever. So don't get hung up on the scale. If you can deal w/ the fact that its just a number and not a true reflection of your progress, then go ahead & use it. If not, don't even bother. The above measures are more important.
RE: eating before the gym -- if its been more than 2 hrs since the last time you ate, I'd say yes, EAT! If I don't I start to get that cold sweat that washes over you when you are experiencing low blood sugar. no thanks on that. Have a shake ready to go or whatever. When I go to work I pack a soft side cooler full of EVERYTHING I need for the day - w/ Atlanta traffic you NEVER know when you're going to get stuck some place so I'm always ready. To that end its really easy to plan ahead and have stuff with you. Lots of the girls & guys on EF use a pre & post workout shake, or even mix protein powder w/ Gatorade for DURING workout.