While I don't diet per-say, I try and limit my calorie intake to no more than 1500 a day (I'm a woman, so that's plenty).
If yer a guy, I would think 1500-2k is a target range (tho I am no doctor), so if you stuck with that and taking a 20 minute walk a day, you'll be doing yourself a world of good.
It's true that yer not going to see immediate results, but just by walking and limiting your intake (in good and "bad" ways, even), you'll gradually lose the weight you wish (and begin to feel better). It's not really healthy for you to lose more than 7-10 lbs a month anyway, so don't fret if you're "only" losing 5 lbs a month. Slow and steady is healthier (ie: you're not crashing your system) and it's a lot easier to keep off in the long run.
Personally, I find that if I eat a green (or chef, if you'd prefer)chef salad for lunch, or a yogurt and fruit, I can have something "good" for dinner (ie: veggie burger or pizza) and still stay within my calorie range for the day. PLus, I cut out most (not all) of my soda drinking if I'm looking to lose a couple of pounds. I like water, anyway, so it's not a HUGE change in my life. SOme people like to squeeze lemon or lime in their water, but I'm good with plain ol' water. ;B
Good luck, in any case!

(And don't get discouraged if you don't look buff in a month!)