I'm also a big advocate of just counting calories (and exercising). There's a really long scientific formula that nutritionists types use to figure out how many calories a person needs in a day just to maintain life (basal metabolism rate) and then you'd add how many calories you burn in exercise, lifestyle activities, etc. This is what I use and I'd type it in here but I've got it on a spreadsheet in my hardrive and it'd be really a lengthy process to get at it when I'm online, given my slow modem. There are tons of sites on the web that use this, even if they don't say so, in "calorie counters" ... a good one is on a site for The Business Plan for the Body ... but note they are trying to sell you a book!
Everyone burns calories differently, that's why one-size-fits-all diets don't work. But a good rule of thumb is to figure out how many calories you are maintaining on and then deduct 500 calories per day to lose a pound in a week (3500). But it's my opinion (uneducated opinion) that no one should go below 1500 and that most people lose weight at that level.
Anyway, good luck on your journey. Hope you find the support you seek here and keep posting.