Calorie counting newbie. Need help!

[MindDimension]

I've decided to swap to CC after struggling with low carbing for a while and starting to do more exercise. I am starting tomorrow using MFP but have a few questions.

What amount of calories a day should I aim for? I was thinking 1700 or is that too high/too low? I have 4 and a half stones to lose.

I want to try and eat as little rubbish as possible (I have a massive sweet tooth!). What do you all generally eat for breakfast, lunch and dinner? I want to try and avoid white bread, potatoes (apart from sweet pots), pasta but will eat brown rice, wholemeal bread/pittas etc.

What are your best snacks whilst calorie counting? What do you have as a little treat now and then? I need to write a shopping list and I'm struggling.

Any help appreciated sorry for the millions of questions!

If you're using mfp I recommend buying some kitchen scales if you don't already have them. mfp generally counts calories by weight of the food and it's been a revelation to me how big and calorie laden the portions were that I was eating before I started weighing pasta, cheese, cereal and so on.
I've only changed my diet recently and trying to stick to a vegetarian diet but normally I don't eat breakfast but have 2 sugary coffees, lunch is porridge or muesli with extra fruit and dinner is things like pasta, salad, tofu, noodles and quorn.
I don't really eat snacks but if I do its things like melon, a banana or natural fat free yoghurt.

I'm on day one.
Breakfast was porridge with banana slices and a tea.
Lunch was just a salad - lettuce carrot and sweetcorn (yes it was dull but I'm saving calories for dinner!)
dinner is 2 fajitas with spicy chicken, salad and sour cream and I can have a Greek yoghurt corner (with almonds and chocolate - that I'm totally addicted to). I'm saving that for this evening as my downfall is the evenings when I'm tired and dh is working late. I can also have 2 more cups of tea. That's just under 1200 calories. I have a stone to lose so I've opted for 1200 on the basis I'm having take away on Wednesday so hoping it won't do too much damage :(

Definitely 2nd the idea of the scales and weighing things. It's too easy to think "oh, that's about 100g" when it actually weighs twice that!
I like mfp because it makes you think about what you're eating. You don't realise how many calories are in some things until it's written there in front of you and you can then make the choice to eat less of that item or not have that biscuit with your tea. I also like the nutritional value aspect so that you can balance your meals and make sure your not lacking vitamins. My iron intake was so low, so I now take a natural supplement and it's made such a difference to my energy levels.